The Republican National Congressional Committee, with an eye on the 2014 election, began zeroing in on Matheson almost the day he was sworn into office for his seven term in January.
Local media have received press releases damning the Democrat on nearly a daily basis. The releases consistently claim Matheson is a flunky for Barack Obama and Nancy Pelosi and just does their bidding to the detriment of Utah values.
Obama and Pelosi would probably take issue with that.
Matheson probably frustrates them more than Republicans for many of his votes that are the Republican side. But the GOP would never give him credit for that while the Democrats howl.
His latest vote to repeal Obamacare got raspberries from his Democratic peers, even while Republicans give him no credit for that.
Then there was his vote earlier this month on the "Working Families Flexibility Act" which is a Republican proposal that makes labor, one of the Democrats' most important interest groups and funding sources, go apoplectic.
The AFL-CIO, in an email that seemed almost complimentary to the NRCC's anti-Matheson posts, strongly condemned him as one of just one of just three Democrats in Congress to vote for the bill, HR1406.
It passed 223-204, with just eight Republicans voting against it, making Matheson a friendly voice among the GOP on an key labor issue.
But don't expect the GOP to appreciate it.
Instead, the AFL-CIO issued a strongly-worded statement claiming Matheson turned his back on working families.
The bill allows employers to offer comp time instead of paying employees time-and-a-half for overtime work.
The labor unions call the measure slight of hand because employers can manipulate the use of comp time to the point that the benefit to the overworked employee is minimal. It also impedes job growth, the detractors say.
"Requiring employers to pay overtime is an incentive for businesses to hire more workers so … overtime hours don't rack up," says the AFL-CIO statement. Eliminating the time-and-a-half pay allows employers to continue to overwork their employees and keep staff levels down, the unions argue.
Even so, watch Matheson painted by the NRCC as a union apologist when he runs in his Republican-dominated district again next year.
It's life as usual for a Democrat in Utah.
But unlike most Democrats in Utah, Matheson has won seven elections in a row. He has done it in Republican-leaning districts and he has done it despite two bouts of gerrymandering by the Republican dominated Legislature to make his district even more Republican than it was before.
And he has done it with lukewarm support from his Democratic base, with the liberals in the party getting increasingly perturbed with his votes that align with the majority of Republicans, not Democrats.
The Republican Legislature may have made a mistake when it redrew the congressional boundaries in 2011 and created such a Republican district for Matheson that he ran instead in a different district that was less intimidating.
Had the GOP given Matheson a more liberal district, he may have had a Democratic primary challenge, as he did in 2010.
That would have forced him to spend more money to get the nomination and weakened his position in the general election. Or it may have given the Republicans a more liberal and easier-to-beat candidate to run against and rid the state of Democrats once and for all.