He will face the winner of an early June runoff primary election between attorney Q. Byrum Hurst, Democrats' preferred candidate, and Arkansas state Sen. Gene Jeffress (D).

Cotton starts off with a strong advantage: while the district is currently held by retiring Rep. Mike Ross (D-Ark.), it leans heavily Republican and the area has been trending toward the GOP for decades. In addition, redistricting made it more favorable for Republicans — President Obama would have only received 37 percent in the new district in 2008, down from the 39 percent he won under the old lines.

In the fourth district, Democrats' favored candidate to face freshman Rep. Rick CrawfordRick CrawfordLawmakers send well-wishes to Scalise on Twitter Moving forward, not back: The U.S.- Cuba relationship How the GOP came to dominate, and be dominated by, rural voters MORE (R-Ark.) barely survived the primary to force a runoff. Arkansas state Rep. Clark Hall (D), the more conservative candidate who has proven a much better fundraiser, took just 39 percent of the vote in a three-way race, while Scott Ellington took 49, just short of the 50 percent he needed to avoid a runoff.

Hall split the more conservative Democratic vote with another candidate and could be able to rally for the next vote on June 12, but if Ellington is the nominee Crawford's edge in the GOP-leaning district will increase.