An ostensibly Republican group is running a variety of ads in targeted states demanding that several White House officials testify in the Senate impeachment trial, according to The Hill.

Republicans for the Rule of Law, led by notorious anti-Trump activist Bill Kristol, is running ads ranging from billboards to television commercials, in four different states. The ads are targeting constituents of four Republican senators who are known for their anti-Trump stances: Mitt Romney (R-Utah), Susan Collins (R-Maine), Lisa Murkowski (R-Alaska), and Lamar Alexander (R-Tenn.).

The ads call for former New York City Mayor Rudy Giuliani, White House Chief of Staff Mick Mulvaney, Secretary of State Mike Pompeo, and former National Security Advisor John Bolton to be forced to testify before the Senate in the ongoing impeachment against President Trump.

Bill Kristol has arguably been the leading anti-Trumper from a supposedly conservative standpoint, having vigorously opposed President Trump’s campaign in 2016 and bankrolling the independent candidate Evan MacMullin. His anti-Trump stance eventually led to the shutdown of his longtime magazine, The Weekly Standard, and Kristol has struggled to maintain relevance ever since.