Former Vice President Mike Pence announced he's running for president on Wednesday, setting up a battle for the Republican nomination with his former boss, Donald Trump.

"That is why today before God and my family, I am announcing I am running for president of the United States," he said during his formal campaign kickoff in Ankeny, Iowa. He was echoing a launch video released earlier Wednesday, in which he cast himself as a Reagan Republican seeking to return America to conservative principles.

Pence's presidential bid places him in a unique position as he becomes the first vice president in modern history to challenge his old boss, who's the current front-runner for the 2024 GOP nomination. Though a loyal second-in-command to Trump, Pence broke with him by refusing to overturn the 2020 election results and presiding over Congress' certification of Joe Biden's victory on January 6, 2021.

Pence argues in the video -- which makes no mention of Trump and features no images of the former president -- that "different times call for different leadership" and that the nation needs a leader "that will appeal, as Lincoln said, to the better angels of our nature."

"We can bring this country back. We can defend our nation and secure our border. We could revive our economy, and put our nation back on a path to a balanced budget, defend our liberties and give America a new beginning for life," Pence says.

After filing with the Federal Election Commission on Monday, Pence is officially launching his campaign in the early voting state of Iowa, which his team views as vital to him securing the nomination. He'll participate in a CNN town hall in the state on Wednesday evening.

Pence -- who's been polling in the single digits -- joins a growing field of Republican hopefuls, which so far has been dominated by Trump and Florida Gov. Ron DeSantis. Former South Carolina Gov. Nikki Haley, who served as ambassador to the UN, is the other former member of Trump's administration running against him. Former New Jersey Gov. Chris Christie, a one-time Trump ally who helped him prepare for the 2020 debates, announced his candidacy on Tuesday with a sharp anti-Trump message.

An evangelical Christian, Pence was picked to be Trump's running mate in the 2016 election in hopes of bolstering his standing among Christian conservatives. While vice president is his most known title, Pence is seeking to reintroduce himself to voters as a conservative who served as an Indiana governor and congressman before hitching his career to Trump.

In speeches, Pence has argued for fiscal responsibility, including calling for reforms to entitlement programs, a renewal of American energy, support for Ukraine against Russia's unprovoked invasion, restrictions on abortion and a return to social conservative principles.

He plans to campaign heavily in Iowa, hitting all 99 counties, as his team sees a path for him to secure the nomination by winning over the state's evangelical conservative voters who have soured on Trump. Later in the week, Pence heads to New Hampshire, which holds the first-in-the-nation GOP primary.

"Evangelicals are very wide open in Iowa, and beyond Iowa, in looking for the candidate who they want to support," Bob Vander Plaats, the influential president of the Iowa conservative group, The Family Leader, told CNN in a recent interview.

Vander Plaats, who has not yet endorsed in the primary but has known Pence personally for years, said that Iowans have received Pence "exceptionally well" during his visits to the state ahead of his formal announcement.

In breaking with Trump, however, Pence may have alienated some of Trump's most loyal supporters. The former vice president has publicly criticized Trump over his assertion that Pence had the authority to overturn the 2020 election results, but he has not taken aim at Trump's character and has repeatedly said that he's proud of their administration's record.

And although some Trump supporters have spurned Pence, other Republicans have applauded Pence for his actions on January 6.

"I think every candidate is going to have their hill to climb or hurdle to cross. And that probably is going to be Mike Pence's," Vander Plaats said, when asked if Pence's standing among GOP voters angered over his actions on January 6 would complicate his path to the nomination.