Rehberg in familiar role as obvious front-runner

U. S. Rep. Denny Rehberg is in the familiar position of being the obvious frontrunner in his re-election bid, but says he is not taking anything for granted in a primary in which he faces challenges from both the left and the right.

Rehberg, who considers hims e l f a " c o n s e r v a t i v e Republican," is facing challenges from two political newcomers.

One, lab scientist Mark French, seems to be riding the rising tide of tea party politics to mount a campaign as someone even more conservative.

So far Rehberg, seeking his sixth term as Montana's sole congressman, has easily outpaced the...