Trump fights to prevent Pence from testifying in Jan. 6 probe.

Donald Trump has appealed a federal judge's order to Mike Pence to testify in the Jan. 6 criminal investigation, arguing that conversations with Pence and other top aides should remain confidential under executive privilege. Pence is a potentially significant witness because he could describe Trump's strategy to overturn the 2020 election and the pressure he was under to participate. Pence, who stood up to Trump's pressure, is a key witness.