Scott Olson/Getty Images

(WASHINGTON) —¬†Donald Trump might never have become president without them. And his quest to regain the presidency might depend on what they do now to stop him.

With back-to-back announcements this week, former Vice President Mike Pence and former New Jersey Gov. Chris Christie joined a swelling roster of Republicans challenging Trump for the 2024 nomination.

They are embracing disparate but perhaps equally impactful strategies to defeat the man they were once so loyal to. Pence is seeking a more delicate way around Trump, paired with an effort to reclaim core tenets of the GOP, while Christie charts a path he describes as straight through Trump.

“Anyone who puts themselves over the Constitution should never be president of the United States,” Pence said Wednesday at his campaign launch in Iowa. “And anyone who asks someone else to put them over the Constitution should never be president again.”

“There’s only one lane to the Republican nomination for president and Donald Trump is at the head of it,” Christie said on ABC’s “Good Morning America” Wednesday. “And you have to go right through him and make the case against him.”

Both men know well how a scattered field contributed to Trump’s rise in late 2015 and early 2016. The Trump campaign greeted their candidacies as fueling a “race for second place,” in a reminder of how far they are behind not just Trump but Florida Gov. Ron DeSantis in early primary polls.

But Pence and Christie also know Trump himself well enough to identify possible vulnerabilities. Pence’s case is both more subtle and more radical — an attempt to reclaim the conservative movement from the man he saw hijack it eight years ago.

The Wall Street Journal editorial page summed his candidacy up in a way Pence could barely improve upon: “Meet Mike Pence, a tested conservative, heir to the Trump economy and the Reagan foreign policy, an evangelical Christian who cites the Word without seeming like a faker.”

Christie is taking a more combative and blunt approach that appeals more to political practicalities than ideology. He is pointing out that the GOP lost ground with Trump at the top of the ticket or indirectly on the ballot in 2018, 2020 and 2022 — and casting him as a policy failure who failed to tame government spending or even complete his signature southern border wall project.

“Eight years ago, you were entertained. I forgive you,” Christie said in New Hampshire Tuesday at his kickoff town hall event. “It’s not funny anymore. It’s not amusing anymore. It’s not entertaining anymore.”

Christie is speaking from a particular experience that’s unique in the field of more than a dozen GOP contenders. He’s the only one running against Trump now who already did that once before, and he carries reminders of how the non-Trump candidates largely ignoring him made him impossible to defeat.

Shortly after his own campaign fizzled seven years ago, Christie saw Trump’s nomination coming and endorsed him back in February 2016, making him the first major former rival to fall into line. Pence put his hopes behind Sen. Ted Cruz two months after Christie backed Trump publicly, though Pence notably refrained from attacking Trump.

Both would become fierce and powerful Trump loyalists. Pence, of course, joined the ticket, where he helped consolidate evangelical and other conservative voters behind Trump. Christie was a key sounding board and outside adviser who was particularly helpful to Trump on debate prep in both 2016 and 2020.

Christie broke publicly with Trump on election night 2020, when Trump began a torrent of misstatements that would carry through the infamous events of Jan. 6. That was the day that sparked the fateful fissure between Trump and Pence, with Pence refusing Trump’s entreaties to seek to overturn the election’s certification in Congress.

“President Trump’s reckless words endangered my family and everyone at the Capitol,” Pence said on Wednesday.

There are signs that the whiplash around Trump has hurt both men in their standing inside the Republican Party. A recent Monmouth University poll found Trump as the far and away front-runner and Pence and Christie viewed more negatively than any other major contenders, with 35% of Republicans viewing Pence unfavorably and 47% saying they have an unfavorable view of Christie.

There could be paths — albeit narrow ones — for both of the newest contenders, in different early-voting states. Pence is putting his chips on Iowa, the only early nominating battleground Trump didn’t capture in 2016. Christie is going all-in on New Hampshire, where GOP Gov. Chris Sununu’s decision to forego a race of his own leaves things wide open.

In its broad contours, the race is starting resemble 2016. A wide range of contenders are challenging Trump, who happens to be more popular inside the GOP than he was at the same point in that election cycle, in a dynamic that could carve up the non-Trump wing of a party that has changed substantially over the past decade.

But the entrance of Pence and Christie to the race points to one big difference this cycle. While Trump was largely ignored early on when he first got in, there’s no danger of that happening again. Some of those who know Trump best will be making sure of that.

Copyright © 2023, ABC Audio. All rights reserved.