Over the course of Senate Minority Leader Mitch McConnell’s career, the publicly mild-mannered Kentucky Republican has inspired passions: Among his allies, heartfelt loyalty and admiration. Among his opponents, deep-seated frustration and enmity.

Friend and foe agree on this much, however: McConnell, a five-term senator, is a skilled practitioner of political hardball who prepares meticulously and approaches even easy campaigns with an aggressive, take-no-prisoners attitude that once caused a supporter to liken him to a “wood chipper.” But McConnell could face no greater test than the 2014 midterm elections.

Democrats and conservative insurgents alike are hoping to upend his bid for a sixth term. First, McConnell has to fend off wealthy businessman Matt Bevin, who with the backing of outside conservative groups could spend heavily to oust the incumbent in a May GOP primary. If he wins, McConnell then has to battle Kentucky Secretary of State Alison Lundergan Grimes, the scion of a powerful Bluegrass State Democratic family with ties to former President Bill Clinton.

In McConnell's corner is Sen. Rand Paul, R-Ky., a Tea Party darling inside and outside of Kentucky who could help the Senate's top Republican keep Bevin at bay. Polls so far indicate that McConnell will face an extremely tight November election against Grimes. But Kentucky's conservative bent and President Obama's growing unpopularity in the state could help McConnell survive.

The Bluegrass State is complicated politically. Democrats run strongly in state and local elections, but struggle in federal contests. Meanwhile, the Tea Party proved its muscle there in 2010 by electing Paul, but has been short on success since then. In the end, the Kentucky Senate race could boil down to whether McConnell's money and well-oiled political machine can overcome the voters' professed disgust with Washington and incumbents.