What did Specter get by switching parties?

Moving the Democrats to 60 votes seems to be an extremely valuable gain for them. A loss of his seniority and the prospect of a tough Democrat primary makes wonder why he switched. However, the Hill reports:

Despite promises from Senate Majority Leader Harry Reid (D-Nev.) that Sen. Arlen Specter (Pa.) would retain his seniority after switching parties, Specter will be put at the end of the seniority line on all his committees but one under a resolution on the floor late Tuesday.

Under the modified organizing resolution, Specter will not keep his committee seniority on any of the five committees that he serves on and will be the junior Democrat on all but one — the chamber’s Special Committee on Aging. On that committee, he will be next to last in seniority. . . . . .

The Pittsburgh Post-Gazette has two prominent Democrats predicting that Specter will face a tough Democrat primary next year.

"I'm pleased that he saw the light and decided he would be a better fit for the Democratic Party and I think you have to allow for his political views to evolve," said former DNC chairman Howard Dean in an interview with the Huffington Post. "But he won't win the Democratic primary by taking the position that you should not have [the Employee Free Choice Act] or a public option for health insurance... If he takes these kinds of views, of course there is going to be a Democratic primary."

In a separate interview with the Huffington Post, Democratic strategist James Carville was equally sour on Specter's recent party switch, calling the defection a potential "major event in terms of how the Senate conducts its business," but "a relatively minor event in political history."

"[Specter] was the least reliable Republican. So he will just switch to become the least reliable Democrat," said the longtime Clinton confidant and author of the upcoming book, "40 More Years: How the Democrats Will Rule the Next Generation." "I wouldn't try to make much more out of it than the political survivor comes up with one more act in a long running play of political survival... The one thing I will give him is I will give him some points for candor for being so upfront about [his switch]."

"I'm not sure this is going to have a great ending," added Carville, who has worked extensively in Pennsylvania politics. "He could get primaried, you know... If [Rep. Joe] Sestak runs, [Specter] will have to fight."

The strange thing is that the Democrats were courting Specter.

In the Democratic Party’s courtship of Arlen Specter, no one may have played a bigger role than Vice President Joe Biden.

Biden has been trying to convince Specter to switch parties for at least the past five years, but those efforts were stepped up once he was sworn in as vice president, a senior White House official said.

Biden has met or spoken on the phone with Specter an average of once a week since the Inauguration. And after Specter became one of three Senate Republicans to support the administration’s stimulus package, those conversations were increased.

In the past 10 weeks, Biden has spoken with Specter 14 times — six in person and eight on the phone, according to the senior official.

Biden said at a fundraiser in Houston Tuesday that he's been trying to convince Specter "that he is really Democrat" for over two decades.

But, he added, "I have been working on that in earnest for the past four years and double-time for the past 100 days."