INDIANAPOLIS (AP) — For a glimpse of red-state politics in the era of Donald Trump, look no further than Vice President Mike Pence’s home state of Indiana, where a grueling Republican Senate race has been dubbed the nation’s nastiest primary.

Two sitting congressmen — Todd Rokita and Luke Messer — and former state lawmaker Mike Braun face off May 8 for a chance to unseat Democrat Joe Donnelly.

They’ve tried to appeal to Trump voters, adopting the president’s harsh immigration rhetoric and even channeling the president by assigning one another derisive nicknames.

But as the race slogs on, some Republicans worry the tone will do lasting damage to the eventual winner’s chances of toppling Donnelly. A Republican National Committee member says the race has “descended into Dante’s Inferno.”