Thank God for Arlen Specter

Senator Arlen Specter’s decision to caucus with the Democrats has, temporarily, pushed the “100 days” storyline into the background, and for that we should all be grateful. (For my sole media effort to correct the  misperception that 100 days matter, see my brief comments with a Canadian journalist here.)  In addition to the blow it inflicts on the Republican Party, at least symbolically, Specter’s defection is another reminder of how difficult it is for moderates to exist in a deeply polarized Senate.  I went back and calculated Specter’s rank, using a generally accepted measure of voting-based ideology (Poole-Rosenthal scores) in each Senate session in which he served dating back to his first in 1981-83 (the 97th Congress).  When it comes to voting, Specter consistently falls in the middle of the pack, with an overall average ranking across 15 congressional sessions as the 52nd most liberal Senator (standard deviation of 4.3).  (Note that I include the President’s rank score in the data used to calculate Specter’s standing).

When the Senate is under Democratic control, the overall mean voting score shifts left, which tends to make Specter more conservative relative to his colleagues; his average rank under Democratic control is 57. Conversely, under Republican control, he ranks slightly more liberal, typically landing right in the middle as the 50th most liberal Senator. On the whole, then, we see that he’s a consistent middle-of-the-road Senator.

So, is his voting record likely to significantly change now that he’s a Democrat?  At first glance, one might think yes.  Indeed, several pundits have suggested as much based in part on political science research on previous party switchers. This research suggests that a switch in party leads to a switch in voting patterns.  But caution is in order; most of this research finds significant changes only in the House.  In the Senate, because of the small sample size, detecting historical trends is much more difficult.

For comparison purposes, I looked up the rankings of four other Senators who switched party affiliation in the modern era to see if it affected their overall Senate ranking.

Senator Years (Year Switch) Pre-Switch Rank Post-Switch
Richard Shelby 1987-2008 (1995) 61st most liberal 77th most liberal
Ben Campbell 1993-2004 (1995) 51 56th most liberal
Jim Jeffords 1989-2002 (2001) 52 52
Joe Lieberman 1989-2008 (2007) 37 34.5

Keep in mind that both Shelby and Campbell switched from Democrat to Republican, while Lieberman ran as an independent after losing the Democratic primary in 2006 but did not join the Republican Party.  After years as a Republican, Jeffords caucused with the Democrats in 2001 but called himself an independent.  So these aren’t strictly comparable to the Specter case.  (The other significant difference, as I discuss below, is that Specter’s switch is motivated by electoral reasons more than ideological ones.)

So based on this limited sample, and subject to all the caveats associated with nominate scores and using ranking, as opposed to absolute voting data (and the different time periods being compared), it appears that Shelby’s voting rank changed significantly, but the other three demonstrate less movement. When we think about the issue a bit more, it’s not surprising that this admittedly limited sample reveals no clear trend in voting patterns after a change in party affiliation among Senators, in contrast to Representatives in the House.

Remember that the House operates under rules designed to empower the majority party, so in periods of high polarization, a switch in parties should tend to lead to a switch in voting (much as political science research has found.) However, this is not necessarily the case in the Senate, where voting is less beholden to party, and much more driven by individual ideology conditioned by constituency and reelection.  In other words, the Senate is not strictly comparable to a parliamentary system, where party leaders often have the means to punish those who cross party lines by, for example, removing them from party lists at election time.  In the U.S. Senate, senators are largely beholden to no one except voters.  Note that based on Poole-Rosenthal scores from the last (110th) Senate, Specter is the third most liberal Republican Senator, topped only by the two Maine Senators Collins and Snowe.  Not surprisingly, all three Republican Senators already voted with the Democrats to pass Obama’s stimulus bill, and there wasn’t a darn thing the Republican Senate leadership could do about it.

All this is a long way of saying that I don’t expect Specter’s rather moderate voting patterns to change very much as a result of the change in party label, since he’s already signaled his willingness to cross parties and vote with the Democrats during the current session if it serves his electoral needs.  Indeed that is what this switch is about – Specter’s 2010 reelection bid.  By switching labels, he can run in the Democratic primary where he (so far) has at least a chance of reelection.  If he stayed a Republican, he was going to get trounced in the primary (the most recent poll had him down 21% among likely Republican voters to the more conservative Pat Toomey).  For Specter, becoming a Democrat was a matter of political survival – not a change in ideology. By negotiating a deal with the Democrats (including Obama’s implicit promise to back him in the Senate race), he’s hoping to avoid a challenge from the Left in the Democratic primary in two years.  If so, I expect him to continue to position himself as a swing voter in a state that is trending Democratic, with his vote determined by his calculations on its likely impact on his Senate reelection chances than on party loyalty.  Note also that he negotiated an agreement to retain his seniority, so the switch doesn’t cost him anything in that regard.

In short, this is a very significant switch for Specter’s electoral chances, not quite so significant for his votes in the Senate.  Of course, if he gets a credible challenger on the Left in Pennsylvania, then all bets are off!

If I get a chance, I’ll talk a bit about the filibuster implications in another post. But my immediate reaction is that I don’t see this having as much impact on moving the Democrats closer toward a filibuster-proof Senate as many have surmised because Specter’s vote was already driven almost entirely by electoral, and not partisan, considerations.  When it serves his purpose – as it did in the stimulus bill when he was able to leverage money to his state in exchange for his support – he will vote Democratic.  But the change in party label isn’t likely to dramatically increase his propensity to do so.


  1. While I generally agree that Specter only switched to avoid a tough primary, and that this doesn’t reflect any ideological shift, do you think that he’ll at least be indebted to the Democrats for allowing him to do this smoothly? The Democrats would probably rather he just lost his primary to someone who would go on to lose the general than for him to switch parties, so he’s got to owe them something, right?

  2. What additional influence does A. Specter have as the Ranking Member of the Judiciary Committee? Also wasn’t he the chairman before he had cancer?

  3. Fraz, that’s a good question. I don’t doubt that conversations occurred, but I’m not sure deals were struck, or at least deals that can be kept. Ideally, Specter gets a commitment from the Democrat party to funnel money to him, or at least not to fund an opponent in the primary. In return, he promises to vote with the Democrats. The problem is that there’s no real way to enforce this agreement. Anyone can run against Specter in the primary, with or without the party blessing. Conversely, it’s not clear that the Dem’s in the Senate can control how Specter votes. Specter’s window of opportunity to fend off challengers in the Democratic primary and the general election is very short, which explains why he already had moved left in terms of voting before the switch in party labels. So I just don’t see how “indebtedness” translates in action.

    I’m not sure that Democrats would prefer that a “true” Democrat beat Specter and then lose the general election, rather than have Specter win reelection as a Democrat. I suspect they’d rather have the party vote.

    Note that not all political scientists agree with my guesstimate that Specter’s switch in party label does not presage a dramatic shift leftward in Specter’s voting. Nolan McCarty, at his blog (see suggests just the opposite. He thinks Specter will move significantly leftward, and quickly.

    My concern, however, is that Nolan is basing his projection on research focused on the House, as opposed to the Senate. I’m skeptical that the dynamics of party switching operate the same way in the Senate. But time will tell.

  4. Fred, my understanding is that Leahy still has seniority over Specter, so Leahy retains chairmanship of the Judiciary committee. As for the Republicans, my guess is that Orrin Hatch becomes the ranking judiciary committee member, but I don’t know that for certain. The full impact of the change may not be known until the Senate reorganizes after the next election, but Specter reportedly would like to chair a key Appropriations subcommittee. My understanding is that he retains full seniority, but seniority is not an iron clad guarantee anymore of a committee chair position. I’m sure conversations have occurred behind closed doors on these matters. As you might imagine, Harry Reid is in a delicate position here.

  5. Matt, thank your for another fact-filled post.

    I may have missed it, but can you review (or reprise) how Specter lost so much ground in the polls among the Republican camp? 21%! Wow!

    I hesitate to follow this chain of reasoning too far, since I confess not to have looked at state-level poll analysis after the election. Still, this big a shift is surprising to me.

    Presumably Specter had a loyal voter base in past runs, so this drop in his numbers is not a sudden counter-revolution by the die-hard right. It astounds me, however, that the conventional storyline is true — that Pennsylvania moderates defected en masse from Republican affiliations to Democratic affiliations.

    The more complicated question for you is, was it a one-off fluke — a matter of everybody cramming into the voting booth to have their say in a very tight Democratic presidential primary — or is the mass defection an issues-driven one that is likely to persist, so long as the Republican platform is stuck where it is?

    Usually one hears about people registering as independents when their parties tick them off. So, let me make the assumption that the number of Dems registered ballooned because of the stakes in that primary: Now that the victor has been declared, what do we know about swing voter allegiances? Is it likely that many of them will in fact re-register for the coming primary as Republicans? Is Specter’s campaign prepared for that contingency?

    In what other states did it happen? Does it happen often, historically? Are these the same pressures that brought down all the other moderate Republicans this past election?

    Did you answer these questions in an earlier post? (And if so, the link is all I’d encourage you to provide.)


  6. Sorry, just to clarify my comment: I meant that the Democrats would probably rather that the remain a Republican, lose to whoever the club for growth candidate is, and then have the Democrat win the general election, which doesn’t seem like an unlikely scenario.

    It almost seems like Specter’s conversion is really a loss for the Democrats, and I guess even more of a deft move by him, since the party apparatus has no way of stopping him from running in their primary and so might as well embrace him, since he’ll probably win that.

  7. Matt, Do you have any figures on how Specter might do if his Republican opponent is Tom Ridge?

  8. Jack, the Club for Growth (one of the most ironically-named groups ever named) is likely a major opponent of Ridge. Ridge is too pro-choice, and too moderate on defense to be viable among the extreme remainder of the Pennsylvania Republican Party, who listen to/agree with the Club For Growth.

    I think the Specter thing solidifies the movement of the Democrats to occupy the center, where the Republicans used to be. The real question is whether the Republicans see this regionalization/marginalization (see Snowe’s NYT op-ed) as a good thing or not. If they do, then the modern two-party system may be in danger, as the Democrats could fracture from being “too wide”. This is a longer view, but it is fascinating to see the evolution of the parties over the past 30 years.

  9. In reference to the earlier comment:

    By now, like the rest of you, I’ve seen the umpteenth finger pointed at the ‘Club for Growth’ PAC. Surely, Matt, you’ll have a demographic reason for Specter’s dilemma that explains why $2m spent by one reactionary PAC remains causally irrelevant.

    But if you feel CfG has been a major player in carrying out purges and giving us today’s ideologically zealous Republican Party, then there are other parts of this story I’d be fascinated to hear.

    How about the ways past party purges were conducted?

    How about PAC influence during a Presidential term? For one thing, can you give us a more definitive account of how deeply Grover Norquist shaped the legislative agenda under Bush II?



  10. @ Martin

    I should have been more clear – CfG isn’t the ONLY player in this “cleansing” of the Republican Party, but it had been influential. Lincoln Chafee attributes his general election loss in 2006 to the pounding he took from the CfG during the primary, and then the guilt-by-association of the increasingly ideologically-pure Republican Party (as symbolized by CfG types).

    So, CfG has been a major player in promoting the removal of RINOs and replacing them with hardliners. Certainly, there have been other groups, but CfG is a big one.

    Primaries allow hardliners to promote/force an agenda onto a candidate that may make him/her less viable in a general election. Likewise, outside funding of candidacy is something of a quid pro quo relationship, meaning candidates are pressured to support ideas they may not have. The Specter and Chafee situations demonstrate both problems.

  11. Sorry for a consecutive post, but I neglected to note that the current frontrunner in PA Republican primary polling is Pat Toomey, by a long shot (even when Specter was in). Toomey also happened to be the president of the Club for Growth for more than 3 years, after getting $2 million from them in his 2004 primary challenge to Specter. Taking as given the PACs are weaker than they used to be, Toomey is still a very formidable individual.

Leave a Reply

Your email address will not be published. Required fields are marked *