Mr. McCain is credited with persuading enough members of his party to agree to a deal that avoid a threatened "nuclear option" -- a change in Senate rules that would curb the minority's ability to obstruct executive branch nominations by filibuster.
The deal broke an impasse between Majority Leader Harry Reid and Minority Leader Mitch McConnell over Mr. Reid's notion to bar filibusters on confirmation votes for certain nominees by letting a simple majority shut off debate. Mr. Reid dropped his threat, for now anyway, and most of the president's nominees are to be confirmed.
In effect, Mr. McCain bypassed the resisting Mr. McConnell in bringing his GOP colleagues to their senses. This comes after Mr. McCain played a key role in getting enough Republican votes (14) to provide the two-thirds majority needed for Senate approval of immigration reform.
The GOP votes on providing a path to citizenship for 11 million immigrants, predominantly Hispanic, are regarded as politically advantageous for his party. The hope is that they will help dent the 70 percent of the Latino vote that favored the Democrat in the presidential race last November.
These two recent McCain interventions suggest that the old maverick is back, after a 2008 incarnation in which he set aside a longstanding reputation as a party contrarian to seek and win the Republican presidential nomination as a staunch, unwavering conservative.
In 2000, the Arizonan sought the nomination essentially in his maverick persona but was no match for George W. Bush, then governor of Texas, who ran as a "compassionate conservative" in a bitter primary fight. Eight years later, Mr. McCain tried again, this time beating Mitt Romney and others for the Republican nomination as a more straight-line conservative himself.
The apparent transformation succeeded in making Mr. McCain the party's standard-bearer against Barack Obama, but again he was outgunned, running an undisciplined campaign capped by the surprise selection of tea party darling Gov. Sarah Palin of Alaska as his running mate.
Back in the Senate, with his presidential ambitions behind him, Mr. McCain has been busy restoring his earlier reputation as a more unpredictable Republican, willing and able to work across the aisle with Democratic senators, many of them longtime friends, to buck the existing congressional stalemate.
The relationship between Messrs. McConnell and McCain had already been a contentious one, particularly regarding the Arizonan's partnership on campaign finance reform with then-Democratic Sen. Russ Feingold of Wisconsin, which Mr. McConnell strenuously opposed. The McCain-Feingold Act eventually was gutted by a Supreme Court decision opening the gates for unlimited corporate giving.
The deal to pass Mr. Obama's executive nominations through the Senate comes at a somewhat embarrassing time for Mr. McConnell, who is facing a well-financed challenge for re-election in Kentucky next year. The state's other U.S. senator, freshman Rand Paul, has been stealing the spotlight there from Mr. McConnell as a libertarian/conservative who propelled himself into the national spotlight with a long filibuster of his own recently.
Mr. McCain's quest for the presidency, from 1999 through 2008, in the end undercut rather than bolstered his political and public reputation. In the 2000 nomination race against Mr. Bush, he was damaged by Bush campaign smears and reacted angrily if understandably. An unconvincing public reconciliation with the man who beat him could not erase the obvious ill will.
In 2008, Mr. McCain was seen as bending himself out of shape ideologically to appear a better fit for a party shifting sharply to the right. Beyond that, at age 72 at the time and running against the youthful and energetic Mr. Obama, Mr. McCain often came off as an outmoded political figure whose time had come and gone.
Back in the Senate, he has begun to restore his old reputation as a more nonpartisan deal-maker in an arena wherein he can still make a significant difference, even possibly for his party, which certainly needs help these days. Now 76 and showing no signs of slowing down, Mr. McCain has an opportunity to help restore a modicum of bipartisanship to the Senate, and to advance history's ultimate good judgment of him.
Jules Witcover is a former longtime writer for The Sun. His latest book is "Joe Biden: A Life of Trial and Redemption" (William Morrow). You can respond to this column at email@example.com.