Voters will consider a full slate of 19 candidates — 11 Republicans and eight Democrats — when they head to the polls later this summer for the U.S. Senate special election primary for the seat vacated by Jeff Sessions, now U.S. Attorney General.

The seat is currently held by Luther Strange, a Republican who was appointed to replace Sessions by former Gov. Robert Bentley, who later resigned from his seat after pleading guilty to misdemeanor campaign finance violations. That reality cast a cloud over the appointment of Strange, who had been charged with overseeing the Bentley investigation.

Now, Strange finds himself in a tight battle to protect his seat in the nation’s highest legislative body.

Strange’s strongest opposition in the state’s GOP primary is likely to come from three relatively well-known Republicans: former Alabama Supreme Court Chief Justice Roy Moore, U.S. House Rep. Mo Brooks and State Sen. Trip Pittman.

As of late, Brooks and Strange have gotten into a back-and-forth endorsement competition, with Sen. Strange garnering more national, institutional support while Brooks has gotten the backing of both locals and representatives of the far-right base.

For example, Strange has been endorsed by the National Rifle Association and his campaign is being aided by the Senate Leadership Fund, a PAC supporting Republican senatorial incumbents. Brooks, on the other hand, has been endorsed by conservative voices such as Sean Hannity and Laura Ingraham, as well as such local grassroots organizations as Alabama Patriots, a tea party group here in the state.

In the last few days, Brooks also picked up support from Mark Meadows, a House Representative who heads up the so-called Freedom Caucus, a powerful group of conservative congressmen.

“Mo Brooks is a fighter,” Meadows said in an email to supporters. “He has the most conservative voting record in the Alabama congressional delegation. He’s got an A-rating from Numbers USA and the NRA. He has proven himself to be a proven constitutional conservative in the mold of Ted Cruz, Mike Lee, Rand Paul and Ben Sasse. We need more like him in the Senate. I’m all-in to help Mo Brooks defeat the D.C. establishment and send him to the Senate. I hope you are too.”

Pittman, a Montrose Republican, is one of the few locals running in the race. While he admits his name recognition isn’t that of Luther Strange or Roy Moore, Pittman declared his candidacy saying his would be a campaign for principles of free enterprise, not popularity.

“We can debate the priorities and decide what government can or cannot do, but we need to be 100 percent behind free enterprise,” Sen. Pittman, who owns a tractor supply company in Baldwin County, has said. “It’s the best way for the most people to reach success.”

That view hasn’t been shared by all of Pittman’s followers, however. During the state’s last legislative session, Pittman’s lone opposition to a bill mandating coverage of autism therapy caused its near defeat through legislative maneuvering — something supporters of the law, which eventually passed with the addition of an age cap, say was “disappointing.” Pittman was the only lawmaker to vote against the bill when it eventually came up for a vote.

“I have great sympathy with people who have autism,” Pittman said at the time. “But as the budget chairman, this bill came through after we passed the budget and there are costs associated with it.”

Also running for the GOP nod are Randy Brinson, Dominic Gentile, Bryan Peeples, James Beretta, Mary Maxwell, Joseph Breault and Karen Haiden Jackson.

On the Democratic side, the front-runner in the primary election is former U.S. Attorney Doug Jones, who is best known for having successfully prosecuted those involved in the infamous 16th Street Baptist Church bombing in Birmingham, which killed four young black girls in 1963.

Other Democratic candidates include Will Boyd, Vann Caldwell, Jason Fisher, Michael Hansen, Robert Kennedy Jr., Brian McGee and Charles Nana Tchienkou.

The only public poll released in the race, a Google Consumers survey of a relatively small number of Alabamians, has Jones losing in a two-way race to Moore, 36 percent to 44 percent. The poll has a margin of error of +/- 5.2 percent.

The special primary election will be held Aug. 15. A runoff will be held on Sept. 26 if necessary. The general election to permanently replace Sessions will be Dec. 12.