WASHINGTON — Senator Mitch McConnell of Kentucky joined House Speaker John Boehner of Ohio on Thursday at the pinnacle of the congressional and Republican power structures in Washington — two establishment deal-cutters, each on occasion frustrated by the other’s inability to rein in their party’s most zealous ideologues.
The pair, formally selected Thursday to lead their party’s new majority control of Congress, will be charged with guiding Republicans on Capitol Hill for the final two years of President Obama’s presidency. Their success or failure could determine whether the GOP can take back the White House in 2016.
McConnell, 72, is taciturn and rarely cracks a smile. ‘‘Why don’t you get a life?’’ he joked to photographers trying to snap photos of him after he was unanimously chosen by his Senate GOP colleagues Thursday to serve as the new majority leader starting in January.
Boehner, 64, is gregarious, chain-smoking, perpetually tan, and fanatical about golf, which McConnell does not play.
But both are seasoned pragmatists steeped in the ways of Washington. They’ve served together in leadership roles for the past eight years and hail from the same region of the country.
Republicans hope their political similarities will help them to avoid conflicts that have emerged in past relationships between a speaker and Senate majority leader of the same party, due to the inherent tensions between the majority-rule House and the slower-moving Senate where minority members have numerous rights.
Their relationship is about to be tested as never before.
Days into Congress’s lame-duck session, conservatives newly emboldened by last week’s election already have served notice that their cooperation is not guaranteed.
They announced this week they want to use upcoming must-pass spending bills to block Obama from taking executive action to curb deportations of immigrants in the country illegally.
Both McConnell and Boehner have stood down Tea Party challenges in the past, and emerged with a tighter grip on the reins of power after navigating the fiscal cliff and last year’s 16-day partial government shutdown over Obamacare.
Pragmatists warn of the potential for another shutdown, but some of the party’s most committed ideologues are looking at how McConnell and Boehner handle immigration as an early test of their leadership.
‘‘The will of the conference is clearly very conservative. The election, what we heard from the American people, was clearly a very conservative message,’’ said US Representative Matt Salmon of Arizona, who is leading the House effort to block Obama on immigration.
‘‘So my guess is that if they want to carry that leadership beyond the next term and win the White House, that we will not march in place, that we will be bold, that we will put difficult things on the president’s desk and not just second-guess what he is willing to sign.’’