This week, Lexington Mayor Jim Gray announced he will challenge three-term GOP Rep. Andy Barr. Some Democrats are ecstatic because Gray is a popular mayor and wealthy construction businessman who carried the 6th CD in his 2016 bid against GOP Sen. Rand Paul, even while President Trump carried it 55 percent to 39 percent. But, he's not the only top-tier Democrat running in this red seat.

In August, retired fighter pilot and Marine Lt. Col. Amy McGrath launched her campaign with a video that went viral and helped her raise over $723,000. Her military profile is impressive, but she only moved back to Kentucky in the last year after retiring from teaching at the U.S. Naval Academy. Gray backers question the true strength of McGrath's grassroots support, but she's staying in the race.

McGrath's trailblazing story and outsider status fit the type of candidate who's gaining traction with Democrats in 2018. But after two terms as mayor, Gray begins the campaign with far more name recognition, the ability to self-fund and strong favorability with area Democrats. Gray, who is gay, led a swift push to relocate downtown confederate statues after the events in Charlottesville this summer.

The May Democratic primary also features African-American state Sen. Reggie Thomas, but he is unlikely to keep fundraising pace with Gray or McGrath. Some speculate that he may drop out and endorse Gray.

If Gray does advance from the May primary, this may be a rare case where the challenger starts with a higher profile than the incumbent. Gray has been a constant media presence as mayor and Democrats' 2016 Senate nominee, while Barr hasn't had a truly competitive race since unseating Democrat Ben Chandler in 2012. And, Gray could be in a position to replenish his coffers quickly after the primary.

There's empirical evidence suggesting Barr, who has voted for the GOP's healthcare and tax bills, would actually start behind against Gray. That has Democrats excited, considering Barr took at least 60 percent in each of the last two elections and Democrats need to put some very red seats in play to win the majority.

But the primary isn't a foregone conclusion, and as Republicans link Gray to national Democrats and litigate his eight year mayoral record, Barr's prospects should improve. For instance, it's unclear how Gray's stance on confederate statues will play with more conservative voters who live in the rural counties outlying Lexington that make up the majority of the 6th CD's population.

In this climate, either Gray or McGrath would be in a position to give Barr a tough reelection race. The contest moves to the Lean Republican column.