Republican incumbent Governor Matt Bevin refused to concede last night in Kentucky’s gubernatorial race, citing unspecified “irregularities” — potentially kickstarting weeks of uncertainty as the closely-watched contest with national implications remains too close to call.

With 100 percent of precincts reporting, Bevin was behind Democratic Attorney General Andy Beshear by 5,333 votes out of more than 1.4 million counted, 49.2 percent to 48.8 percent. Libertarian candidate John Hicks received 2 percent.

The history-making evening also saw Republicans decisively hold onto the governorship in Mississippi despite a fierce Democratic challenge, while electing Kentucky’s first black attorney general. Democrats, meanwhile, took complete control over the Virginia statehouse for the first time in 26 years.

The Associated Press said it could not declare a winner, owing to the tight margin. The Democratic National Committee and Beshear’s campaign, however, claimed victory.

“My expectation is that he [Bevin] will honor the election that was held tonight,” Beshear said in a speech to supporters. “That he will help us make this transition. And I’ll tell you what, we will be ready for that first day in office, and I look forward to it.”

And Democrat Amy McGrath, who is running in a long-shot bid to unseat GOP Senate Majority Leader Mitch McConnell in 2020, said simply: “All I have to say is: Mitch, you’re next.”

Bevin, however, called it a “close, close race” and said he wasn’t conceding “by any stretch.” He added, “We want the process to be followed, and there is a process.”

Although Bevin has not outlined his next steps, Kentucky law provides for a variety of possible avenues. There is no mandatory recount law in Kentucky. Bevin may request counties recanvas their results, which is not a recount, but rather a check of the vote count to ensure the results were added correctly. Bevin would need to seek and win a court’s approval for a recount.

Bevin could also mount a legal challenge to the election results, assuming he could identify sufficient grounds.

Regardless of the final outcome, the razor-thin margin in the race did not come as a surprise to Republicans. Although Trump carried deep-red Kentucky by 30 points in the 2016 presidential election, Bevin has long been very unpopular for a Republican in the state, owing in part to his numerous spats with striking public school teachers and his plan to address a growing pension crisis.

Bevin significantly underperformed the rest of the GOP ticket on the ballot in Kentucky on Tuesday, as Republican candidate Daniel Cameron handily won his race to become the state’s next attorney general. Cameron made history as the first African-American to be elected Kentucky Attorney General and the first Republican to hold the post in more than 70 years.

In a strong indicator that Bevin is unpopular among Kentuckians, Cameron received 774,864 votes in his 15-percentage-point win — while Bevin garnered only approximately 700,000 votes for his marquee gubernatorial bid. It is highly unusual for down-ballot races to attract more voter interest than gubernatorial contests.