Former US Vice-President Mike Pence has opened his bid for the Republican nomination for President with a firm denunciation of former President Donald Trump, accusing his two-time running mate of abandoning conservative principles and being guilty of dereliction of duty on Jan. 6, 2021.

On that perilous day, Pence said, as Trump supporters stormed the US Capitol and the president falsely insisted his Vice-President could overturn the election results, Trump “demanded I choose between him and our Constitution. Now voters will be faced with the same choice.”

Pence, launching his campaign at a community college in a suburb of Des Moines, is the first Vice-President in modern history to challenge the President under whom he served. While he spent much of his speech criticising Democratic President Joe Biden and the direction he has taken the country, he also addressed January 6 head-on, saying Trump had disqualified himself when he declared falsely that Pence had the power to keep him in office.

Trump’s statements about mass voting fraud led a mob of his supporters to storm the US Capitol, sending Pence and his family scrambling for safety as some in the crowd chanted, “Hang Mike Pence!”

“I believe anyone that puts themselves over the Constitution should never be President of the United States, and anyone who asks someone else to put them over the Constitution should never be President of the United States again,” the former Vice-President said.

Yet he did not rule out anyone when asked on Fox News Channel if he would support Trump if the former President wins the GOP nomination.

“I will absolutely support the Republican nominee in 2024, especially if it’s me,” Pence said, “I think we’ve got a great group of men and women running for this nomination, and I do believe we’ve got better choices in the days ahead.”

Insurrectionists loyal to President Donald Trump storm the U.S. Capitol in Washington on Jan. 6, 2021. Photo / AP

Pence has spent much of the past two-and-a-half-years grappling with the fallout from that day as he has tried to chart a political future in a party that remains deeply loyal to Trump and filled with many who still believe Trump’s lies that the 2020 election was stolen and that Pence somehow could reject the results.

While Pence has criticised Trump, working to step out of the former president’s shadow while laying the groundwork for his own run, he has generally done so obliquely, reflecting Trump’s continued popularity in the party. But as Pence made his pitch to voters for the first time as a declared candidate, he did not hold his tongue.

He accused the former President of abandoning the conservative values he ran on, including abortion.

Pence, who supports a national ban on the procedure, said, “After leading the most pro-life administration in American history, Donald Trump and others in this race are retreating from the cause of the unborn. The sanctity of life has been our party’s calling for half a century-long before Donald Trump was a part of it. Now he treats it as an inconvenience, even blaming our election losses in 2022 on overturning Roe v. Wade.”

Trump has declined to say what limits he supports nationally and has blamed some midterm candidates’ strong rhetoric for their losses last November.

Pence also bemoaned the current politics of “grudges and grievances,” saying the country needs leaders who know the difference between the “politics of outrage and standing firm.”

“We will restore a threshold of civility in public life,” he pledged

Trump did not immediately respond to the speech, but his supporters shot back.

“The question most GOP voters are asking themselves about Pence’s candidacy is ‘Why?’” said Karoline Leavitt, a spokeswoman for a Trump-backing super PAC.

With Pence’s entry into the race, on his 64th birthday, the GOP field is primarily set. It includes Trump, who’s leading in early polls, Florida Governor Ron DeSantis, who remains in second, former United Nations Ambassador Nikki Haley, South Carolina Senator Tim Scott and former New Jersey Governor Chris Christie.

Pence’s campaign will test the party’s appetite for a socially conservative, mild-mannered and deeply religious candidate who has criticised the populist tide that has swept through his party under Trump. Pence, in many ways, represents a throwback to a party from days past. Unlike Trump and DeSantis, he argues cuts to Social Security and Medicare must be on the table and has blasted those who have questioned why the US should continue to send aid to Ukraine to counter Russian aggression.

Pence and his advisers see Iowa — the state that will cast the first votes of the GOP nominating calendar — as key to his pathway to the nomination. Its caucusgoers include a large portion of evangelical Christian voters, whom they see as a natural constituency for Pence, a social conservative who often talks about his faith.

But Pence faces steep challenges. Despite being one of the best-known Republican candidates in the crowded field, he is viewed sceptically by voters on both the centre and the right. Trump critics consider him complicit in the former President’s most indefensible actions, while many Trump loyalists have maligned him as a traitor, partly to blame for denying the President a second term.

Republican presidential candidate former Vice-President Mike Pence poses for a photo with an audience member at a campaign event. Photo / AP

A CNN poll conducted last month found 45 per cent of Republicans and Republican-leaning independents said they would not support Pence under any circumstance. And in Iowa, a March Des Moines Register/Mediacom Iowa Poll found Pence with higher unfavourable ratings than all of the other candidates it asked about, including Trump and DeSantis.

But Pence, who has visited Iowa more than a dozen times since leaving office, has been warmly welcomed by voters during his trips.

His Wednesday audience in an auditorium decorated with red, white and blue balloons included several Iowa Republican officials, including former Iowa Rep. Greg Ganske, whose time in Congress overlapped briefly with Pence’s.

“I’m here because we’re friends,” said Ganske who represented the Des Moines area in the House. Still, he said he hadn’t figured out who he was going to support in the caucuses. “We have a lot of good candidates,” he said.

John Steuterman, a 44-year-old insurance executive, said he was drawn to Pence’s experience in the White House and was “tired of the negativity” another Trump term would bring.

“Mike Pence is a decent man. He seems like a regular guy, as much of a regular guy who has been at the centre of the executive decision-making of the most powerful country in the world,” he said.

But asked whether Steuterman was locked in for Pence in the lead-off caucuses, he said, “I’m not married to the idea, but I’m going to watch and listen and I’m going to follow this guy.”

It was the same for Dave Bubeck, who lives in Grimes and praised Pence as “a super professional guy,” “statesmanlike,” and “a man of high character” — with the capacity to serve as president. “But I think there are other good candidates,” too, he said, adding he would “wait and see how it all shakes out.”

Asked why he wasn’t sold on Pence, Bubeck said, “Maybe he’s a little too nice ... I don’t know if he’s tough enough for what we need right now. That would be my hesitancy.”

Pence’s decision to focus on January 6 reflects his advisers’ strategy that the Capitol attack has to be confronted directly.

His argument resonated with Ruth Ehler, a retired teacher from West Des Moines who attended the speech.

“The Constitution is the document of our country and I stood by him on Jan. 6 when he followed the Constitution. If that’s where he feels he differs from our past president, it’s a great point for him to make,” Ehler said.

And yet, Ehler could not say whether she was leaning toward supporting Pence in the caucuses.

- Jill Colvin, Thomas Beaumont, AP