Accompanied by Republican Gov. Chris Sununu, Pence signed the paperwork and paid the $1,000 filing fee at the secretary of state's office while supporters chanted "Four more years!" in the hallway. "In so many ways, the movement that has transformed our country, rebuilt our military, revived the American economy, restored and strengthened the constitutional foundation of our courts, has America standing tall in the world again, began here in the Republican primary in New Hampshire," Pence said "I couldn't be more honored, on behalf of the president of the United States, to have his name on the ballot."
While Trump won the 2016 New Hampshire GOP primary, he lost the state in the general election to Democrat Hillary Clinton. And Sununu was one of the few successful Republicans during the 2018 midterm elections, when Democrats won both of the state's congressional seats and took control of both chambers of the state Legislature.
The Republican Party in several states has issued official endorsements of the president, and several states are canceling their GOP primaries altogether. In New Hampshire, Trump is expected to face at least three challengers : former Massachusetts Gov. Bill Weld, former South Carolina Gov. Mark Sanford and former Illinois Rep. Joe Walsh. And state GOP bylaws require the party to remain neutral, though some Trump supporters considered trying to change the rules last year.
Pence said each state should decide whether to cancel its primary. "But I know there's a long tradition when there's an incumbent president of a particular party, some states decide to save the expense of a primary, and we respect that," Pence said. "We see it as an affirmation of the president's record and his leadership and the overwhelming support that President Trump has among Republicans and frankly all across this country."
During a speech at Saint Anselm College on Thursday afternoon after the filing, Pence said he "couldn't be more proud to serve as vice president to the most pro-life president in American history." Pence warned attendees that the Trump administration's "progress could be lost in one bad day in November a year from now."
"It's remarkable to see leading candidates for the highest office in the land in the Democratic Party today that are advocating ideas like abolishing private health insurance, legalizing illegal immigration," Pence said. "It's extraordinary to think how far left the other party has gone."
Meanwhile, one of Trump's most prominent Republican critics, former Ohio Gov. John Kasich, said Thursday in an appearance at the University of New Hampshire that he does not intend to file for the state's 2020 presidential primary.
Associated Press writer Hunter Woodall in Manchester, N.H., contributed to this report.