(CNN) — Former Vice President Mike Pence filed paperwork for the 2024 Republican presidential nomination on Monday, setting up a showdown with his last-election running mate, former President Donald Trump.
Pence is scheduled to formally announce his bid for the nomination this Wednesday before a CNN forum tonight.
The former vice president’s entry 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 for his claim that the then-Vice President had the authority to overturn the 2020 election results, but has not targeted Trump’s character and has repeatedly said he is proud of his administration’s record.
Trump, by contrast, has already unleashed personal volleys against other 2024 Republican challengers, including Florida Gov. Ron DeSantis.
Pence, a 63-year-old former congressman and former governor of Indiana, 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 “Christian, conservative and Republican, in that order.”
He rose through the ranks of the Republican Party on Capitol Hill in the early 2000s, eventually becoming the third Republican in the House of Representatives from 2009 to 2011. He was elected Governor of Indiana in 2012.
In the Trump White House, Pence was a loyal adviser, touting the administration’s successes as well as the president’s. He chaired the White House coronavirus task force, which coordinated the administration’s response to the Covid-19 pandemic and laid the groundwork for vaccine distribution shortly after Trump and Pence left office.
However, Pence broke with Trump over the former president’s actions following the 2020 election, which are now the subject of a special counsel investigation.
Trump tried to publicly and privately pressure Pence to reject key swing states 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 part of the mob chanted death threats against him.
In April, Pence testified at the special counsel’s investigation, the first time in modern history that a vice president was forced to testify about the president he served. He had offered details about his conversations with Trump leading up to and after Jan. 6 in his autobiography, “So Help Me God.”
Pence said that what he has related in interviews and in his memoirs is “the same story that I would tell in that scenario, and it is the truth.”
Pence has criticized Trump on occasion as he pondered a presidential run, including in a speech in February 2022 that showed the deep rift between them:
“President Trump was wrong,” Pence said then. “He had no right to annul the elections.”
Trump, for his part, has said he was “very disappointed” by Pence on the day the electoral votes were certified.
The former vice president has already tried to bring up his political differences with his former boss, including over welfare programs, abortion and US support for Ukraine in its war against Russia.
Despite his name recognition, Pence has been polling in the single digits, trailing well behind Trump and DeSantis.
His acceptance among Republican voters has been mixed, sometimes with admiration and respect, other times with insults and hostility.
At a National Rifle Association (NRA) convention in April in his home state of Indiana, Pence was greeted with some boos, with one attendee telling CNN the disapproval stemmed from the It happened on January 6, 2021. 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 believed he did his duty under the Constitution in that very situation.