Maryland Democrats to decide in Tuesday primary elections who will go up against GOP Gov. Hogan

Maryland voters head to the polls on Tuesday, and for Democrats, voters will choose who they want to run against incumbent Republican Governor Larry Hogan.

RELATED: Maryland Primary Voting Guide: What you need to know before heading to the polls June 26

For the Maryland Democrats, the gubernatorial primary is shaping up to be a potentially close race. Five people are running for the nomination, but Prince George's County Executive Rushern Baker and former NAACP President Ben Jealous are looking to be the two top contenders.

"We are the only candidacy that's surged. We started off in fourth place and now we're in first place and that's the most important thing, the other front-runner kind of just stayed stuck where he's been. I used to run and I know we're about to lap him, and that feels really good," said candidate Ben Jealous.

A poll from The Baltimore Sun found Jealous was ahead of Baker, with the rest of the candidates trailing behind. But whichever Democrat wins on Tuesday is going to have their work cut out for them. That's because Larry Hogan has a 71 percent approval rating and is one of the most popular governors in the U.S.

"You want someone who faced the firing squad and came through and produced. People know there will be challenges and you go out there and face them up front and you've been honest with people. And that's what's going to making the difference in this race," says Prince George's County Executive Rushern Baker.

These numbers are especially unique because only 26 percent of Maryland voters are Republicans, outnumbered by Democrats 2-1. Hogan is confident but says winning re-election as a Republican when many "experts" expect a "blue wave" of Democrat voters will not be easy.

"I think there's probably is somewhat of a wave, but the good news is some of that blue wave is coming out just to vote against Republicans, but here in Maryland most of the blue wave that's coming out, actually approve of the job that I'm doing," says Gov. Hogan.

In Maryland's U.S. Senate Race, there are seven candidates challenging incumbent Senator Ben Cardin, including Chelsea Manning, the transgender Army private who served time for leaking classified information to wiki-leaks. And for the GOP, 11 Republicans are running for the Senate seat to oppose Cardin.

In western Maryland, the 6th Congressional District race features eight Democrats and four Republicans. The winners will face off in November to fill the seat being left vacant by John Delaney, who is leaving Congress to run for president.

There are also two hotly-contested county executive races. Voters in Montgomery County will choose a successor to Isiah Leggett, with six Democrats vying for the seat. In Prince George's County, voters will pick a successor to Rushern Baker, with ten candidates are competing for this open seat.

Polls open at 7 a.m. and close at 8 p.m.

FOX5 has the complete rundown on who's running in our Maryland primary voting guide.