Hobson is fresh off of Moore's losing bid, which ended in a surprise defeat after Moore faced allegations of sexual misconduct involving teenage girls.

In his announcement speech outside of the state capitol building in Montgomery, Hobson defended Moore from the accusations, calling Moore's loss the "biggest political assassination of our time," according to the Montgomery Advertiser's Brian Lyman, and tied himself to the embattled former judge.

ADVERTISEMENT "I believe in what Judge Moore believes in and I will stand for his values," Hobson added.

Both of those reactions could hurt Roby's standing among ardent Moore and Trump supporters. While Roby won her 2016 reelection bid, the 8 point margin was far closer than expected, an outcome many attributed to backlash from Trump supporters.

But knocking off Roby won't be easy — she's held the seat since the 2010 election, and another primary challenge from state Rep. Barry Moore (R) could split the anti-Roby vote.

Roby represents a large swath of the state, including part of Montgomery in the central part of the state, as well as areas all the way down to the state's southeast border. Moore's campaign held each of its final two events in Roby's district as it looked to shore up support among its core group of supporters.