South Dakota senator who serves as the minority whip will replace Mitch McConnell in January

John Thune, the Republican senator for South Dakota, will become the new Senate majority leader after winning an internal party ballot on Wednesday for the position left vacant by the imminent retirement of Mitch McConnell.

His elevation – following the second round of a vote among Republican senators that was held under secret ballot conditions – propels him into a key role in advancing Donald Trump’s agenda when the president-elect returns to the White House in January.