A couple of months ago I looked at the 2012 election and determined that Carl DeMaio would make a formidable challenger to incumbent CA-52 congressman Scott Peters. The National Republican Congressional Committee message tested DeMaio and found him leading Peters 49%-39% in a hypothetical match-up.
There are good reasons to be skeptical of DeMaio holding such a big lead. The poll was conducted by the NRCC. They gave out positive attributes for DeMaio and, I assume, not for Peters. That'll push DeMaio's numbers up. Yet while DeMaio is unlikely leading by 10%, he is likely fairly even with Peters, if not leading. You don't expect a non-scandal plagued sitting congressman to be trailing before the opponent is even in the race. Usually the challenger is closing the gap by campaigning and getting better known. So DeMaio would likely be a great candidate for the Republicans and Scott Peters should indeed be scared of his candidacy.