The polling in the race has been all over the board, from a big lead early for Matheson to a 15-point lead according to Love's internal polling in September.
"It seems to be coming back into balance, dead even, with both spending a lot of time and effort to tear each other apart, so I think that's where we're at," Monson said. "They're going at it pretty aggressively, and it's left a fair number of people in doubt about where we are."
Matheson said he's not surprised by the tight race. He expects that in the final weeks voters will start to focus more intently on the candidates and that he will fare well.
"I said six months ago just like I say today I've always anticipated a close race and I think that's what it's going to be," Matheson said.
Ivan DuBois, a senior adviser to the Love campaign, said that the Key poll doesn't reflect other polls, Love's internal polling or what the campaign sees on the ground. "We do know this is a close race against a member of Congress who is heavily funded by outside money from PACs and special interest groups."
"We believe grass-roots efforts and conservative principles will carry the day," he said.
Matheson is leading among women voters, 46-38, with a large number undecided, which shows a significant shift from a 10 point deficit among women voters in a recent poll for KSL and the Deseret News.
He is also attracting support from 26 percent of self-identified Republicans, which is not as strong as his usual showing, Monson said.
"To be real safe he should be closer to a third than closer to a quarter, so it's exactly why it's close," Monson said. Matheson is getting 93 percent of the Democratic support and 57 percent of independents.
The 43 percent mark is not a solid showing for either candidate, Monson said, particularly Matheson as the incumbent. But Matheson can also make a glass-is-half-full argument that the race has turned in his favor since the earlier polls.
With a tight race getting tighter, the Love campaign and national Republicans have focused on tying Love even more closely to presidential candidate Mitt Romney.
Love is airing a television ad built on top of a robo-call from Romney. The recorded call started going out to voters about two weeks ago and the new television ad began airing on Friday. In it, Romney says Love "is the only candidate in the race who will fight to rein in reckless spending and to lower taxes."
Mailers juxtaposing Matheson's image with Obama and Love with Romney have also been hitting voters' mailboxes during the past few weeks.
According to the Key poll, Romney is drawing 71 percent support to Obama's 20 percent in Utah.
DuBois said Josh Romney endorsed Love early in the campaign and the Romney family has been supportive throughout, but the campaign is accentuating what it believes is an important difference between the two candidates.
"You can judge a candidate by the friends they keep and Barack Obama has chosen to support Jim Matheson and Matheson has chosen to support Barack Obama, and that's a powerful message and I think voters should know that," said DuBois.
Matheson said the Love campaign is stressing its ties to Romney because "this is all they've got to run on."
"Her record [as mayor] in Saratoga Springs has all kinds of problems and her position on the issues are so out of step with mainstream Utah voters," Matheson said. "Right now she's just trying to stand on other people's shoulders, but based on the record and issues I'm not sure she can do that."
He said Love wants to eliminate the Department of Education, privatize Social Security and add to the middle class tax burden all issues where Romney is closer to Matheson's position than Love's.
Matthew Burbank, a political science professor at the University of Utah, said it's not surprising that Love would cozy up to Romney, and it may sway some voters who are eager to vote for Romney but don't have strong allegiances in the 4th District race.
"People who may be drawn into this are people who, yes, are very interested in the presidential race but don't have strong opinions in races down the ballot, and the Love people are giving them an easy option," Burbank said.
Matheson's counter-argument has to be that he is an independent, distancing himself from both parties, as he has in the past. But that is a tougher sell, Burbank said, if voters might be making up their minds on Election Day.
The Key Research survey found Republicans likely to coast to victories in other races in the state. Gov. Gary Herbert is leading Democrat Peter Cooke 65 percent to 19 percent. Sen. Orrin Hatch is beating Scott Howell, 61 percent to 22 percent. Those samples had a margin of error of plus-or-minus 4.4 percent.
The 4th District race had a smaller sample and a larger margin, plus-or-minus 7 percent. But Monson said based on what other polls in the district are showing, he is confident with the numbers.