Republicans on Capitol Hill have chosen a power duo to shepherd President-elect Donald Trump’s domestic and foreign policy agenda.

Sen. John Thune (R-S.D.) was elected Senate majority leader on Wednesday, and Speaker Mike Johnson (R-La.) is officially running unopposed within his party to lead the House. The full chamber won’t officially vote on the House speaker until January. But with Trump’s backing and a Republican majority, Johnson, a staunch supporter of the incoming president, is expected to remain in the top job.

Both Thune and Johnson will have their work cut out for them. Thune can only afford to lose three Republican votes —the size of the new majority— on any legislation or nominee. Johnson’s majority is continuously shrinking as Trump taps House members to serve in his Cabinet. Republicans in the House will have only a four-seat advantage over Democrats.

Thune beat out Sen. Rick Scott (R-Fla.), who was widely seen as the candidate favored by Trump’s base, to lead Senate Republicans. The win positions Thune, a well-respected insider, to serve as a foil to Trump’s more anti-establishment tendencies.