Former Vice President Mike Pence on Monday filed the paperwork for his bid for the 2024 Republican presidential nomination, setting up a clash with his running mate of elections past, former President Donald Trump.
Pence is set to formally announce his candidacy on Wednesday ahead of a CNN presidential town hall that evening.
The former vice president's entrance into the race sets up an unpredictable battle between the former president who helped incite an insurrection in his bid to cling to power and his once-loyal vice president who played a role in stopping that effort to thwart democracy.
Pence 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.
Trump, in contrast, has already unleashed personal barbs at other 2024 Republican rivals, including Florida Gov. Ron DeSantis.
Pence, a 63-year-old former congressman and Indiana governor, was selected as Trump's running mate in 2016 in part because he could help Trump shore up the GOP's socially conservative base.
An evangelical Christian who has long opposed abortion rights, Pence frequently says he considers himself "a Christian, a conservative and a Republican, in that order."
He rose in the GOP's ranks on Capitol Hill in the early 2000s, ultimately becoming the third-ranking House Republican from 2009 to 2011. He was elected governor of Indiana in 2012.
In Trump's White House, Pence was a loyal deputy, touting the administration's successes as the president's. He chaired the White House's coronavirus task force, which coordinated the administration's response to the Covid-19 pandemic and laid the groundwork for the distribution of vaccines shortly after Trump and Pence left office.
However, Pence broke with Trump over the former president's actions in the wake of the 2020 election, which is now the subject of a special counsel investigation.
Trump publicly and privately sought to pressure Pence to reject key swing state results in the vice president's ceremonial role leading Congress in counting electoral votes. On January 6, 2021, Trump was slow to stop his supporters from attacking the US Capitol while Pence was inside and some of the mob were chanting death threats against him.
In April, Pence testified in the special counsel investigation, the first time in modern history that a vice president had been compelled to testify about the president he served. He had offered details about his conversations with Trump leading up to and after January 6 in his autobiography, "So Help Me God."
Pence said what he's relayed in interviews and in his memoir is "the same story that I would tell in that setting, and it's the truth."
Pence has been critical of Trump at times as he weighed a presidential bid, including in a February 2022 speech that showcased the lasting rift between the two men.
"President Trump was wrong," Pence said then. "I had no right to overturn the election."
Trump, for his part, has said Pence "very greatly disappointed me" on the day the electoral votes were certified.
The former vice president has already sought to draw policy differences with his former boss including on entitlement programs, abortion and America's support for Ukraine in its war against Russia.
Despite the name recognition, Pence has been polling in the single digits, well behind Trump and DeSantis.
His reception among Republicans voters has been mixed, sometimes met with admiration and respect, other times vitriol and hostility.
At a National Rifle Association convention in April in his home state of Indiana, Pence was greeted with some boos, with one participant telling CNN that the disapproval was due to January 6. But he received a standing ovation at an event hosted by the Herbert Institute for Public Policy in Utah later that month when he mentioned that he believes he did his duty under the Constitution on January 6.
This story has been updated with additional reporting.