Who might replace Mitch McConnell? An early look at the race for the next Senate GOP leader

Washington — Senate Minority Leader Mitch McConnell announced on Wednesday that he will step down from leadership after November's elections, teeing up a race for the top Republican post in the Senate that has been years in the making. 

McConnell's retirement from leadership marks the end of the longest-serving leadership term in Senate history, after 17 years at the party's helm. And with months until the conference gathers after November's elections to select a new leader, the announcement kickstarts a lengthy campaign for the job.

"Whoever replaces him is going to have big shoes to fill," Sen. Susan Collins, a Maine Republican, told reporters on Wednesday.