Voters head to the polls in Alabama on Tuesday for the state's Republican U.S. Senate primary.

The race to fill Attorney General Jeff Sessions' former seat has featured an endorsement from President Donald Trump and attacks on Senate Majority Leader Mitch McConnell. In Alabama, a deep-red state that overwhelmingly backed Trump, the Republican who emerges from the field will most likely win the special election.

Several Republicans are vying for the seat, but only three are considered serious contenders: Luther Strange, Roy Moore and Mo Brooks. Strange, the incumbent, was appointed to fill the Senate seat in February after Sessions became the top U.S. law enforcement official.

An average of recent polls shows the front-runner is Moore, who was removed as Alabama chief justice in 2003, with about 32 percent of support. Strange followed with roughly 28 percent. Brooks, a congressman and member of the far-right House Freedom Caucus, has about about 17 percent, according to RealClearPolitics. If no candidate wins 50 percent of the vote, the top two go to a runoff next month.