This is Utah not New Jersey. Every year is a bad year for Democrats. Not a single county in Utah went Democratic. The worst showing Romney had in the whole state was Summit county, and he won that one by 5 points. Well Summit County wasn't part of the 4th district. The Republican should have won the race by double digits. If they didn't it's because they had a bad candidate.
Democrats haven’t performed as badly as you might think for Utah’s Congressional districts. Matheson has been one of the luckiest examples, and he has done so since 2000 despite running under GOP-favored lines. His father had had success as Governor, and won his races as a Dem as both Gerald Ford and Ronald Reagan were at the top of the ticket.
Fact is, Mia Love was THE best performing candidate against Matheson in his Congressional career. She lost by 768 votes, which was .3%. Polling data indicated it was going to be close, and it was. Now, there are some other examples as to why she narrowly lost, one being that the Libertarian candidate was on the ballot (who took a key 3%). Others were possibly racial (when she beat a White GOP opponent at a primary convention, he employed race baiting, and I have no doubt some of that seeped over into the general), also that Matheson had support from key RINOs like Huntsman, and that Matheson is a higher-ranking official in the Mormon church than Mayor Love.
In any event, for someone who performed as well as Mayor Love did, it would be her honor to make a second run against Matheson.
Matheson is a hereditary Democrat with a great reputation passed along from his father ... by all appearances he not a loony leftist. I would go so far as to state that if all Rats were even vaguely like Matheson I would not hate Rats. At some point he will need to switch parties. If not, in Utah the stupidity / Marxism of the national Rats will almost undoubtedly take him down.