Politico's Thrush: Birther movement is “a proxy for racism”

From Glenn Thrush's July 31 Politico post:

A whopping 58 percent of Republicans either think Barack Obama wasn't born in the US (28 percent) or aren't sure (30 percent). A mere 42 percent think he was.

That means a majority of Republicans polled either don't know about -- or don't believe the seemingly incontrovertible evidence Obama's camp has presented over and over and over that he was born in Hawaii in '61.

It also explains why Republicans, including Roy Blunt, are playing footsie with the Birther fringe.

Surprise, surprise: Birther sentiment was strongest in the South and among the 60-plus crowd - presumably because seniors can't log on to the Internet and rely on rumor, word of mouth and right-wing talk radio.

When do we start a serious dialog about the Birther movement being a proxy for racism that is unacceptable to articulate in more direct terms?