A recently circulated political ad featuring Colorado’s two Republican candidates for U.S. Senate has been making waves in conservative circles.  

The rally began with a preemptive apology: Sen. Elizabeth Warren (D-MA) wouldn’t have time to do her customary post-rally selfie session; she had to rush to catch a plane to South Carolina ahead of next week’s primary.

Conservative activist and talk radio host Karen Kataline is calling on fellow Republicans to change their voter registration and become unaffiliated, so they can vote for “the weakest Democrats in the primary.”