Darby Libertarian Dan Cox might just be Republican U.S. Rep. Denny Rehberg's No. 1 enemy in Montana's U.S. Senate race.
Sure, incumbent U.S. Sen. Jon Tester, a Democrat, holds the seat and a massive money edge over Rehberg. But Cox and his libertarian politics could put the Democrat back in office for six more years.
Tester and his allies know it. Their anti-Rehberg messaging is aimed at blurring the distinctions between Rehberg and Tester, and driving libertarians toward Cox: If you want to limit the surveillance state, cut the national debt and deficit and curtail governmental intrusion into private lives, Tester's logic goes, don't vote for me — but don't vote for Rehberg, either.