Talking Points Memo examines the role of John McCain in moving the Senate in a more moderate direction:

Whether it’s immigration reform, the budget, or President Obama’s nominees, a faction of more moderate Republican senators are increasingly splitting from both their leadership and the tea party and partnering with Democrats on key issues.

The growing signs of division are remarkable after years of exceptional Senate GOP unity under the reign of Senate Minority Leader Mitch McConnell (R-KY), during which minority use of the filibuster to thwart governance has soared to unprecedented heights.

This week, large numbers of Republicans, led by Sen. John McCain (R-AZ), broke with McConnell and voted with Democrats to secure the confirmation of controversial Obama nominees to the Labor Department, Environmental Protection Agency and Consumer Financial Protection Bureau. In all eight cloture and confirmation votes, McConnell voted “no.”

And later in the piece:

On immigration, 14 Republicans joined every Democrat in voting to comprehensively overhaul the system and offer unauthorized immigrants a path to citizenship.

On the budget, numerous Republican senators are urging conservative colleagues to stop blocking conference negotiations with the House, and are pushing for a long-term budget agreement with Democrats that includes new revenues — anathema to the tea party.

McCain has led the dissent in each of these cases, earning effusive praise from leading Democratic senators and prompting jokes this week by Democratic aides that he is the new minority leader.