Past criticism of Trump becomes potent weapon in GOP primaries

As Republican candidates jockey for position in contests for open U.S. Senate seats, support from former President Trump has become the most coveted prize to be won, an instant differentiator that can help them stand out from a crowded field.

By the same token, opposition researchers are discovering the most potent weapon against potential rivals: past comments critical of Trump, or acknowledgement that Trump lost to President Biden in the 2020 election.