Chris Hansen will become the National Republican Senatorial Committee’s new executive director, installing the 34-year-old Republican operative as a key player for the Senate GOP as it tries to expand its expected 52-member majority in 2018. 

Hansen’s move to the group has been rumored for weeks, ever since Sen. Cory Gardner of Colorado became the odds-on favorite to be the NRSC’s chairman. Hansen is Gardner’s chief of staff. 

Alex Siciliano, Gardner’s spokesman, confirmed the move to Roll Call. 

Hansen and Gardner have worked together since the lawmaker ran for the House in 2010, when Hansen managed his campaign. The young operative also ran Rep. Mike Coffman’s successful 2012 re-election effort, when Democrats made the Colorado lawmaker one of their top pickup targets of the year. 

In 2014, Hansen managed Gardner’s campaign for the Senate, when the Republican unseated Democratic Sen. Mark Udall in one of the year’s most competitive races.

Hansen will replace current NRSC executive director Ward Baker, who helped the Senate GOP unexpectedly hold its majority this year despite defending a plethora of Republican-held seats in blue-leaning states.

The map in 2018 looks very different for the GOP: Democrats must defend 10 seats in states that Donald Trump won, while defending only one (Nevada), which Hillary Clinton won.

Natalie Rogers, Gardner’s deputy chief of staff, will replace Hansen as the lawmaker’s top aide.