Following the election, Republicans will control the Senate with a 53 to 47 majority, but one question remains -- who will become the new Senate majority leader? Outgoing leader Mitch McConnell will remain in Congress but will step aside as the longest serving party leader in history.

Helfrich’s resignation comes during a year of considerable turnover in leadership for both parties. Republicans will enter next year’s session with new leaders in both chambers, while Democrats will have a new House speaker and majority leader and a new Senate majority leader.

Contests for Senate majority leader and the suddenly open House Republican conference chair position headline GOP leadership elections on Capitol Hill this week, with open jockeying for both posts. Senate Republican Whip John Thune of South Dakota,