The Obama campaign has released a new video slamming Mitt Romney for his failure to stand up to birther conspiracy theorist Donald Trump.

The video compares Romney to John McCain — who memorably stood up to some conservative wingnuts during the 2008 campaign — by declaring: “McCain and Romney: Two Republican nominees. Only One willing to lead.”

The video comes in advance of Romney’s fundraiser with Trump, which will take place Tuesday night in Las Vegas. When Romney was asked whether Trump’s crazy rants make him uncomfortable, the Republican nominee claimed that he’s not responsible for the actions of his surrogates.

“You know, I don’t agree with all the people who support me and my guess is they don’t all agree with everything I believe in,” Romney said. “But I need to get 50.1% or more and I’m appreciative to have the help of a lot of good people.”