DENVER — Former governor John Hickenlooper's ethics woes have unsettled a Colorado Senate race that Democrats consider one of their best chances of flipping a Republican-held seat, with the quirky brewery owner's reputation taking a hit with voters within days of the state's primary.

The two-term governor and former Denver mayor is on the defensive after the Independent Ethics Commission found he violated a state gift ban in 2018 when he accepted a ride in a Maserati limousine at a conference in Turin, Italy, and traveled on a private jet owned by a home builder to Connecticut for the commissioning of the USS Colorado submarine.

The commission voted Friday to impose fines of $2,750 on Hickenlooper — $2,200 for the private jet trip and $550 for the limousine ride in Italy. The penalty represents what is believed to be an estimate for each, although the commission said the lack of evidence presented by the two sides made it difficult to figure out the true costs.

Earlier this week, Hickenlooper insisted voters would look past the violations.

“I’ve campaigned twice in difficult elections, and it’s clear I have a relationship with Coloradans through thick and thin,” said the former petroleum geologist during a primary debate Tuesday. “They are going to recognize these as smear attacks.”

But Hickenlooper’s behavior during a remote hearing held by the five-member panel last week overshadowed the ruling itself and injected momentum into the campaign of his primary opponent, former Colorado House speaker Andrew Romanoff. The winner of the June 30 contest will challenge Sen. Cory Gardner (R), considered one of the most vulnerable incumbents in the November election.

The U.S. Senate seat is crucial to Democratic hopes of wresting the majority from Republicans, who hold a 53-to-47 advantage but are playing defense in more seats — 23 — including several in Democratic-leaning and swing states.

After his short-lived run for president last year, Hickenlooper was considered an ideal Senate recruit for the Democratic Party — a well-known candidate who had won statewide races twice and a former small-business owner who opened the first brewpub in Colorado. In his recent ads, Hickenlooper emphasizes how as governor he took the state from 40th in job creation to first.

Facing ethics complaints, Hickenlooper, 68, refused to testify at the video conference and appeared last week after only the commission, some of whom he appointed while governor, held him in contempt of a subpoena.

His taxpayer-funded attorney, Mark Grueskin, argued in a legal filing in May that the video conferencing format denied the candidate’s due process rights to consult in person with counsel and asked for a delay.

On Friday, Grueskin asked the commission to purge the contempt charge. The panel refused.

With mail ballots arriving this week, the backlash from what one commissioner termed the former governor’s “disrespect for the rule of law” is causing some voters to reconsider their preferred candidate.

“I thought he was a good governor, and he did good things for the state,” said Anne Holton, 72, a retired assistant attorney general and registered Democrat who planned to vote for Hickenlooper.

“But if there were more to come out from the ethics commission, and if there were something I just thought ‘I can’t live with that,’ I would vote for Romanoff,” added the former state employee. “I always drop my ballot off at the last minute.”

Hickenlooper’s ethics issues burst onto the national stage on June 5 when President Trump tweeted about the commission holding the former governor in contempt saying he, “Got caught big time with his hand in the cookie jar. Should be the end of his Colorado Senate bid. Makes no difference, we already have a GREAT SENATOR.”

Gardner’s unabashed embrace of Trump’s policies on immigration and the environment is widely considered a liability in a state where Democrats swept the 2018 midterms, winning the governorship and both houses of the General Assembly. Polls over the past eight months consistently showed Hickenlooper beating the 45-year-old Yuma Republican by double digits in a state Hillary Clinton carried by five percentage points in 2016.

“Republicans are going to be tied to the president whether they like it or not,” said Jessica Taylor, Senate and governors editor for the Cook Political Report, which rated the race a toss-up.

“I think Cory Gardner can run ahead of Trump, but can he run ahead of him enough to win?” she asked, saying Hickenlooper’s ethics issues “have given Gardner an opening.”

Both Hickenlooper and Gardner hit the airwaves with six-figure ad buys recently, with Gardner highlighting how Congress enacted nine of his bills, his effort to bring the U.S. Space Command to Colorado and his work delivering protective equipment to the state during the coronavirus pandemic. There is no mention or image of Trump in the latest ad.

Democratic campaign operatives said that regardless of the ethics scandal, they were confident Hickenlooper’s widespread name recognition and popularity among voters will ensure that he prevails over Romanoff in the primary, and ultimately, Gardner in the general election.

“I don’t think this rises to the level of derailing a campaign — it’s a storm in a tea cup,” said Colm O’Comartun, former executive director of the Democratic Governors Association. “More and more in politics people have already made up their minds, and we are looking at a very small group in the middle who are swing voters.”

In Colorado, that group isn’t so small. Four of every 10 voters are registered unaffiliated and are eligible to cast ballots in the primary. The remaining 60 percent is divided almost evenly among Democrats and Republicans.

The once-purple Centennial State is tilting left, with liberal Sen. Bernie Sanders (I-Vt.) winning the March 3 presidential primary with 37 percent of the vote.

Like Sanders, Romanoff supports Medicare-for-all and the Green New Deal, making him a favorite among Colorado’s growing number of millennials. Hickenlooper favors strengthening the Affordable Care Act and supports a plan to reach net-zero emissions by 2050.

Young people are phone banking for Romanoff, calling thousands of voters each week, seeking to boost the momentum provided by the ethics controversy.

“Hickenlooper’s the first person in history to be held in contempt by the ethics commission and that shows contempt for voters,” said Michele Weindling, a regional organizer with the Sunrise Movement, a nonprofit formed to address climate change. “He defied a subpoena to testify because he didn’t want us to have answers to his ethics inquiry before the primary.”

In the first of a series of debates before the primary, the former governor said Tuesday that “a dark money political group” was behind the ethics complaint filed in 2018 by former state Republican House speaker Frank McNulty. In the half-hour forum, Hickenlooper said commissioners absolved him of 95 out of 97 allegations in the document, including flights on company planes owned by friends. The constitutional gifts ban, enacted by voters in 2006, requires officials to report gifts that exceed a token value.

Romanoff called on Hickenlooper to drop out of the race, saying that his questionable conduct endangered Democrat’s chances of beating Gardner.

“He represents a threat we cannot afford,” said Romanoff, who lost two statewide races in 2010 and 2014 after he served eight years in the state House from 2000 to 2008. Even though he won the state caucuses and emerged from the state assembly with top billing on the primary ballot, Romanoff trails Hickenlooper in fundraising.

Veteran independent pollsters in Colorado questioned if Romanoff could keep the former governor’s ethics violations at the forefront for voters dealing with the coronavirus pandemic, economic fallout and the civic unrest after the death of George Floyd in Minneapolis police custody.

“The question is whether Romanoff can get it sufficiently in the political atmosphere,” said Floyd Ciruli, director of the Crossley Center for Public Opinion Research at the University of Denver.

“It clearly hurt the governor’s reputation as being honest — he’s always tried to maintain a reputation of being clean,” he added. “As a matter of fact, he took a shower once with his clothes on to argue he wasn’t going to go negative in campaigns.”

Republicans, who concede that Gardner’s allegiance to Trump endangers his reelection prospects, said that Democrats are nervous about how the ethics commission investigation will play out. They emphasized the panel dropped most of the charges in the complaint because they were outside the one-year statute of limitations, adding the record points to a pattern of improper travel.

“The fact that the DSCC sent out one of their top lawyers to basically oversee the Hickenlooper defense is indicative of the concern they’ve got,” said Dick Wadhams, a Republican political consultant and former state party chairman.

Republicans argue that despite a reputation for being well-liked, Hickenlooper won reelection to a second term as governor in 2014 by about three percentage points and his initial run for the office in 2010 with 51 percent of the vote in a three-way race.

“John Hickenlooper’s popularity is an inch deep and a mile wide,” said Colorado Republican Party Chairman Ken Buck, who is also a member of Congress.