GOP defends Trump as John Bolton book adds pressure for witnesses

Senators faced mounting pressure Monday to summon John Bolton to testify at President Donald Trump's impeachment trial even as Trump's lawyers mostly brushed past extraordinary new allegations from the former national security adviser and focused instead on corruption in Ukraine and historical arguments for acquittal.

Senate plunges into President Donald Trump's impeachment trial

The U.S. Senate plunged into President Donald Trump's impeachment trial on Tuesday with Republicans abruptly abandoning plans to cram opening arguments into two late-night sessions and Democrats arguing for more witnesses to expose Trump's "trifecta" of offenses.