Too late. The people of KY already did. In 2014, McConnell faced Louisville businessman Matt Bevin in the Republican primary. The 60.2% won by McConnell was the lowest voter support for a Kentucky U.S. Senator in a primary by either party since 1938.
This appearance in '14 at CPAC was noteworthy. Probably helped him.
“If I am given the opportunity to lead the U.S. Senate next year, I won’t let you down"
McConnell faced Democratic Secretary of State Alison Lundergan Grimes in the general election. Although polls showed the race was very close, ultimately McConnell defeated Grimes by 56.2%–40.7%, 15.5 percentage points – one of his largest margins of victory, second only to his 2002 margin.
He's good to go, "leading" the GOP Senate machine, until 2020.