A "compromise candidate" is a person who is chosen or agreed upon as a solution to a disagreement or conflict. This individual is often seen as a middle-ground option that can help bring people together and reach a consensus. Full definition
So compromise candidates may not make it to the general election, even if they would receive more support. (politics.stackexchange.com)
That debate is largely over the degree to which casting a ballot in a two - party system implicates one in the evils represented by ethically compromised candidates. (firstthings.com)
It does not follow that centrist or compromise candidates such as the Lib Dems will be more likely to win - only that the least popular can not win. (politics.co.uk)