Newt Gingrich’s triumph in a Minnesota GOP straw poll of support for potential 2008 candidates is meaningless, but the message circulated by state party leaders is not:

Delegates received a two-page letter warning that McCain is widely viewed as the front-runner, creating “a significant risk that a moderate candidate will get the Republican nomination in 2008.”

The letter was signed by some of the state party’s most influential leaders, including National Committeeman Brian Sullivan, former chairman Chris Georgacas, former National Committee member Jack Meeks, and Mike Wigley, a founder of the Taxpayers League of Minnesota.

While both McCain and Giuliani have been “steadfast supporters of the war on terror,” the letter said, “between them they have supported tax hikes, free speech restrictions, amnesty for illegal immigrants, gay marriage and abortion.”

Can John McCain win a GOP nomination if he faces attacks like this? I remain skeptical, though the Tradesports futures market still puts his probability of winning at 45 percent.