Voters head to the polls today in West Virginia to decide a contentious Republican U.S. Senate primary and candidates for the state's three U.S. House seats.

The GOP primary battle to take on incumbent Democratic Sen. Joe Manchin is a heated three-way race between Rep. Evan Jenkins, West Virginia Attorney General Patrick Morrisey, and former coal company CEO Don Blankenship. Loyalty to President Donald Trump has been a key issue in the primary, and allies of Senate Majority Leader Mitch McConnell, R-Ky. have recently stepped up their campaign to prevent Blankenship, who served one year in federal prison for conspiracy to violate mine safety and health standards, from winning the nomination.

President Trump won the state in the 2016 election by more than 40 points, but Democrats are hoping Manchin can hold the seat in a midterm election year where the political landscape may tilt in their favor but they are defending ten U.S. Senate seats in states Trump won in 2016.

Polls in West Virginia close at 7:30 p.m. EST.

WATCH LIVE TONIGHT: You can watch livestreaming coverage of all the primary action starting at 7 p.m. ET on ABCNews.com or on the ABC News app available on the Apple App Store, Google Play Store, Apple TV App Store, and Roku Channel Store.

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