“The guy’s toxic,” said Stewart, who has courted Bannon’s support. “There’s no support for him, even among the establishment. He hasn’t been able to pass the president’s agenda.”

Most other GOP Senate candidates are more circumspect, acknowledging voters’ frustrations with Washington while cautious not to antagonize McConnell and his well-funded political operation.

“If he can get health care, immigration, tax reform done, terrific,” Michigan businessman Sandy Pensler told the Detroit News when he launched his campaign earlier this week. “Otherwise … he shouldn’t be the leader. It’s a results-driven analysis for me. So far he hasn’t gotten it done.”