With all the grassroots animosity being heaped on Mace and Rice, you would think they were goners in the June 14 primary. To win, they each have to bring in 50 percent plus one of the votes. If they don’t meet that, they’ll have to compete in a runoff against their top challenger.

But it’s more complicated than that. South Carolina has nonpartisan voter registration. There is no barrier limiting primary voting to just Republicans. Anti-Trump independents or Democrats could decide to influence in two heavily Republican districts by casting their vote in the GOP primary. Their votes could save both Mace and Rice.

Consider the case of the late John McCain, the maverick senator who was unpopular with Trump voters when he ran for reelection in the GOP Senate primary in 2016. McCain wound up winning only 51 percent of the vote. Kelli Ward, a pro-Trump former state senator, won 40 percent. McCain almost certainly lost among registered Republicans but won by running so strongly with the one-third of Arizonans who are registered independents — and who could vote in the GOP primary.

A similar dynamic could save Representative Liz Cheney, a vocal Trump critic, who faces several challengers in her August primary in Wyoming. The Trump-backed choice is Harriet Hageman, a land-use attorney and former candidate for governor.