Say this for the man: He went out the way he came in. As a squishy careerist tool.

Ever the prosecutor, Sen. Arlen Specter delivered a critical attack of partisan politics in his self-described “closing argument” Tuesday morning on the Senate floor…

Referring to primary challenges as a form of “sophisticated cannibalism,” Specter called out to his moderate colleagues and would-be senators of this cycle: Sen. Bob Bennett of Utah, who lost his nomination at the party convention because activists thought he was too centrist, as well as Murkowski, who lost her primary earlier this year but will likely be certified the winner as a write-in candidate.

“Congressman Mike Castle was rejected in Delaware’s Republican primary in favor of a candidate who thought it necessary to defend herself as not being a witch,” said Specter. “The spectacular reelection of Sen. Lisa Murkowski on a write-in vote in the Alaska general election and the defeat of other tea party candidates may show the way to counter right-wing extremists.”

An attentive Murkowski had no visible response to Specter’s praise, although the two are close. She stayed with Snowe until the end of the speech to greet Specter afterward, embracing him and giving him a kiss on the cheek.

He also took a shot at Roberts and Alito for “judicial activism” and even tossed in a gratuitous reference to “Justice Bork — excuse me … Judge Bork,” just to rub a little salt in one of the more lasting wounds he inflicted on social conservatives. Says the Examiner’s Timothy Carney, marveling at the Bork quote, “His closing argument was an angry, petty, mean, self-serving screed that betrayed a total lack of self-awareness.” How un-self-aware did it get? Dude:

Mr. Specter, who changed parties after he determined that his support for President Obama’s economic stimulus made him unelectable in a Republican primary, said that under the current political environment, a senator could be severely penalized for one vote cast out of thousands, making compromise impossible.

“Repeatedly, senior Republican senators have recently abandoned long-held positions out of fear of losing their seats over a single vote or because of party discipline,” Mr. Specter said.

Remember, this is a guy who became a Republican in the first place only because he thought he couldn’t win the Democratic primary for Philadelphia D.A., then flatly admitted to switching parties last year because he thought it would improve his chances of being reelected. And switching parties also meant switching principles, or whatever the word “principle” might mean as applied to Specter: Remember how his views on health care “evolved” just in time to justify voting for ObamaCare?

You can watch the whole thing at C-SPAN but here’s the bit of him whining about cannibalism. Somewhere a single tear rolls down Charlie Crist’s cheek. Click the image to watch.