Arlen Specter’s departure from the Republican Party confirms the obvious. As Specter put it, “The Republican Party has moved far to the right” since the days of Ronald Reagan.

Republican National Committee Chairman Michael Steele unwittingly dotted the “I” in “right” when he denounced Specter for his "left-wing voting record."

Adding an extra heaping of classlessness, Steele said:

“Specter didn't leave the GOP based on principles of any kind. He left to further his personal political interests because he knew that he was going to lose a Republican primary." To top it off, Steele said Republicans "look forward to beating Sen. Specter in 2010, assuming the Democrats don't do it first."

Such disrespectful treatment is sure to distress Susan Collins and Olympia Snowe, the two remaining moderate Republican Senators from Maine. Steele had previously threatened to withhold funds from all three of them because they voted for President Obama’s stimulus package.

Pressure on Collins and Snowe to switch parties, or at least become independents, will mount, as Obama and Harry Reid are likely to offer them plums. And even if they don’t bolt like Specter, the Democrats are in a veto-proof position once Al Franken takes his rightful seat.

But before you fall over backwards cheering Arlen Specter, notice how craven he was back in 2006 during the debate on the Military Commissions Act.

Specter, who fancies himself a constitutional scholar and protector, recognized that the act would deny people their fundamental right of habeas corpus, which goes all the way back to the Magna Carta. During the debate, he introduced an amendment to preserve habeas corpus. Otherwise, he said, the bill will “turn the clocks back 800 years.”

Specter’s amendment failed, and he turned around and voted for the Military Commissions Act anyway.

A true profile in cowardice.

That was the time to switch parties. It’s a little late now.