Mike Pence announces he's challenging Donald Trump in 2024 presidential race

Former Vice President Mike Pence announced in a video on Wednesday that he is running for president against his former boss -- Donald Trump -- because, he said, "Different times call for different leadership."

In the video, however, Pence did not once mention or show an image of Trump or the event which caused their split: the Jan. 6 attack on the U.S. Capitol by a pro-Trump mob.

Instead, Pence cast the contest as a battle for a country that is "in trouble" under President Joe Biden and what Pence calls the radical left.

"We're better than this. We can turn this country around, but different times call for different leadership. Today, our party and our country need a leader that will appeal, as [Abraham] Lincoln said, to the better angels of our nature," Pence said in the video. "It'd be easy to stay on the sidelines -- but that's not how I was raised. That's why today, before God and my family, I'm announcing I'm running for president of the United States."

Pence is set to kick off his campaign alongside family and supporters on Wednesday afternoon in Iowa, an early-voting state he plans to barnstorm to beat Trump on the road to the Republican presidential nomination.

The former congressman and Indiana governor filed paperwork on Monday with the Federal Election Commission to make his candidacy official.

Pence was a loyal No. 2 to Trump until Jan. 6, 2021 -- the climax to Trump's campaign to try and pressure Pence to reject their Electoral College loss, which Pence was constitutionally unable to do as vice president.

Later, Pence said he hoped Trump "would come around in time, that he would see the cadre of legal advisers that he surrounded himself with led him astray, but he hasn't done so."

While Trump has since repeatedly criticized Pence, some others have argued the former vice president should take on Trump to a greater extent.

For example, whereas fellow presidential candidate Asa Hutchinson condemned Trump following Trump's indictment by a New York grand jury -- on charges Trump denies -- Pence sounded similar complaints as the GOP's MAGA wing to try and delegitimize the case. He discouraged the protests the former president called for but noted their First Amendment right to peacefully assemble.

"Pence is very methodical and strategic," said Doug Heye, a former communications director for the Republican National Committee. "He's going to take Trump head-on on those things where, politically, he sees the best advantage -- and with an eye to History, as he's obviously trying to do."

Others, like GOP donor Dan Eberhart, compliment Pence but are concerned with his level of support.

"Mike Pence is a true conservative and a great public servant. He just doesn't have the support among Republicans that he needs to be competitive. His net favorables with Republicans are 18%. That's comparable to Dan Quayle when he ran for president," Eberhart said.

However, Heye said it would be premature for anyone to count Pence out.

"That's why you see so many people getting in," Heye said. "They see a vulnerability with Trump, very clearly. And while he'll certainly have some obstacles, it's clear that Pence knows his weaknesses better than anyone else."

Pence is expected to court the evangelical vote, a significant block of Iowans, and campaign on Ronald Reagan-era conservative values. In his launch ad, he showed a photo of himself as a congressman in the Oval Office with Reagan.

Setting the groundwork for a campaign, Pence has already visited Iowa at least eight times this year, and allies launched a super PAC, called "Committed to America," in May. He also published a memoir, "So Help Me God," in November.

"It's hard to think of anybody who would have more credibility in that community than Mike Pence," said Heye.

Expanding primary field

Pence is not the only Trump loyalist-turned-challenger jumping into the 2024 race this week.

Former adviser and former ABC News contributor Chris Christie launched his campaign on Tuesday in New Hampshire, another pivotal early-voting state.

Pence joins a crowded primary field -- where early polls show Trump is ahead of his comPetitors right now.

Thus far, Pence and Trump's major GOP primary challengers are: Christie, Ron DeSantis, Nikki Haley, Hutchinson, Vivek Ramaswamy and Tim Scott.