The Texas Senate is set to gavel in Tuesday for the impeachment trial of Attorney General Ken Paxton, a political reckoning of years of alleged corruption that could lead to his permanent ouster from office.

The fate of Paxton, a 60-year-old Republican, is in the hands of GOP senators with whom he served before winning a statewide race to take charge of the attorney general’s office in 2015. In an era of bitter partisanship, the historic proceeding is a rare instance of a political party seeking to hold one of its own to account for allegations of wrongdoing.