First lady Michelle ObamaMichelle LeVaughn Robinson ObamaMichelle Obama criticizes lack of diversity in politics: one side is 'all white, all men' Obama interrupts Michelle's appearance with 25th anniversary tribute Michelle Obama: Young people feel what's happening now 'not what they were taught' MORE's foray onto the campaign trail hit another bump Thursday, when she identified Sen. Mark UdallMark UdallDemocratic primary could upend bid for Colorado seat Picking 2018 candidates pits McConnell vs. GOP groups Gorsuch's critics, running out of arguments, falsely scream 'sexist' MORE (D-Colo.) as "a fifth-generation Coloradan."

"As a fifth-generation Coloradan, Mark understands what makes this state special," the first lady said during a campaign rally in Denver. "He understands the values of independence and fairness, all the things here folks believe in."

The only problem: Udall was actually born in Tucson, Ariz., where his father, Rep. Mo Udall (D-Ariz.), represented the state in Congress for 30 years. 

Udall's opponent, Rep. Cory GardnerCory Scott GardnerRepublicans jockey for position on immigration Bipartisan bill would toughen North Korea sanctions, require Trump's strategy GOP senators push for delay of ObamaCare insurer tax MORE (R-Colo.), has made a point of emphasizing on the campaign trail that his family's Colorado roots extend five generations back. 

The comment was quickly noted by reporters on the ground, and highlighted in a web video from the Republican National Committee.

Udall's campaign, however, insists it was not a mistake. They say that although Udall was born in Arizona and lived there through high school, his mother was a fourth generation Coloradan.

The campaign also noted that Udall's parents met when his father played for the Denver Nuggets. The congressman appeared on the team's roster during the 1948-49 season.

The first lady, who has been campaigning hard for Democrats in close Senate races, has come under fire for a series of missteps on the trail. 

Earlier this week, the White House was criticized after an email transcript of the first lady's campaign appearance in Iowa referred to Rep. Bruce BraleyBruce BraleyOPINION | Tax reform, not Trump-McConnell feuds, will make 2018 a win for GOP Ten years later, House Dems reunite and look forward Trump: Ernst wanted 'more seasoning' before entertaining VP offer MORE (D-Iowa) as the "Democratic candidate for governor." Braley is running for Senate.

That happened just days after the first lady repeatedly botched Braley's name during a separate campaign event, calling him "Bruce Bailey."

In her second appearance in Iowa, Obama made light of the flub, admitting the last time she was there, she "got it wrong, a couple of times."

She went on to joke that she also confuses her daughters' names and occasionally calls the president Bo — the name of one of the family's dogs.

"But although I may have slipped up on Bruce's name a couple of times, what I know, I got right are Bruce's values," Obama said.

The White House dismissed both Iowa incidents as insignificant to the campaign.

"Anybody who heard the first lady’s comments yesterday would come away with the impression that she did a good job advocating for him and motivating voters to support his campaign," press secretary Josh Earnest said. "So I think it was worth doing, and I think she did it well. I think the number of people who heard her remarks is significantly higher than those of you who are closely reading the transcript."

At an event later in the afternoon at Colorado State University, Udall addressed the controversy.

"I want to share with you a little story about how silly things have gotten. As we were driving up here from Dever…a few bloggers started criticizing the first lady for saying I'm a fifth generation Coloradian," Udall said. "Let me set the record straight. I do have two parents, and when my dad played for the Denver Nuggets he met my mother in the late 40s, they fell in love, and they moved to Arizona. But I want to tell you that I listened to my mom, I came back to Colorado."

Udall added that his great-grandfather was a Coloradan who had taught at the university a century ago. 

This post was updated at 6:24 p.m.