Answer: I'm not sure either is more electable
Given the history of former governors running for Senate in states that generally vote for the opposite party, I'm not sure it will matter much if Trone or Alsobrooks make the ballot. Consider Phil Bredesen in 2018, a popular former Democratic governor in Tennessee who lost an open seat in the state to Marsha Blackburn by around 11 points, even in a blue wave year. Or Evan Bayh, who sought a return to the Senate in Indiana in 2016, only to lose by 10 points to Todd Young. The list continues ... Ted Strickland in Ohio in 2016, Linda Lingle in Hawaii in 2012 ... I just don't think that a former governor, even a popular one, can really overcome the partisanship of a state when it comes to the Senate.
—Mary Radcliffe, 538