Sen. Bob Corker, R-Tenn. (center), talks to reporters on Capitol Hill. He decided Tuesday not to seek a third term. Corker is the first Senate retirement of the 2018 election cycle.
Senator John McCain leaves after a procedural vote on healthcare on Thursday, as the Senate was to vote on moving head on health care with the goal of erasing much of Barack Obama's law.
Brendan Smialowski/AFP/Getty Images
Senate Majority Leader Mitch McConnell of Kentucky faces a tough choice — irritate the GOP base and work with Democrats or risk passing legislation that is not very meaningful.