Richard Painter, longtime Republican and former ethics lawyer for President George W. Bush, announced on Twitter Monday that he's running for U.S. Senate as a Democrat in Minnesota.

Driving his decision: President Trump. Painter, a frequent critic of Trump on cable news and social media, said on Twitter that his decision to not only run for office but to run as a Democrat is attributable to Trump and "the broken system that got us where we are today." "Americans are fed up!" he added.