Former Vice President Mike Pence capped his first full day as a formally declared presidential candidate with a CNN town hall on Wednesday night in Iowa, casting himself as an experienced, traditional conservative.

But his challenges in a Republican primary field dominated by former President Donald J. Trump were evident throughout the roughly 90-minute event.

Mr. Pence sought at once to align himself with Trump administration actions that were cheered by many Republicans, while drawing both explicit and oblique contrasts with Mr. Trump, the front-runner for the nomination. It is a difficult balancing act for any Republican candidate, but especially for Mr. Trump’s former vice president, who has so far gained little traction in the polls.

He also sought to emerge as the leading social conservative in the race, quoting Scripture and emphasizing his opposition to abortion and transgender rights.

“I’d put my arm around them and their parents, but before they had a chemical or surgical procedure I would say, ‘Wait, just wait,’” Mr. Pence said, when asked about his opposition to gender-transition care for young people even when their parents consent.

Here are five takeaways:

Trump’s legal troubles were a thorny topic.

A number of the Republican 2024 hopefuls have struggled with how to distance themselves from Mr. Trump, who maintains a strong grip on a slice of the Republican base.

Mr. Pence confronted that issue early in the town hall, when he was asked about the possibility of another indictment of Mr. Trump. Federal prosecutors have informed Mr. Trump’s legal team that he is a target of an investigation concerning his handling of classified documents after he left office.

“It would be terribly divisive to the country,” Mr. Pence said, saying he “would hope” that an indictment would not go forward. “It would also send a terrible message to the wider world.”

He added, “No one’s above the law,” when pressed on whether he thought prosecutors should not pursue an indictment even if they believed Mr. Trump had committed a crime. But he suggested that the situation involving Mr. Trump presented “unique circumstances here.”

Asked whether, as president, he would pardon Mr. Trump if he was convicted of a crime, Mr. Pence instead shifted to speak lightheartedly about his chances in the race.

“I’m not sure I’m going to be elected president of the United States,” he said. “But I believe we have a fighting chance. I really believe we do.”

Mr. Pence has faced his own scrutiny over his retention of documents, but the Justice Department declined to pursue charges.

He was firmer in criticizing Trump over Jan. 6.

Hours before the town hall, Mr. Pence issued his sternest denunciations to date of Mr. Trump, lacing into him over his actions on Jan. 6, 2021.

Mr. Pence, who had helped legitimize Mr. Trump in the eyes of some conservatives in 2016 and was long his loyal lieutenant, rebuffed Mr. Trump’s pressure campaign to seek to effectively reject now-President Biden’s victory in the Electoral College. He drew threats of “Hang Mike Pence” from some in the pro-Trump mob that attacked the Capitol that day.

During the town hall, moderated by Dana Bash, Mr. Pence again made clear that he and Mr. Trump had “a difference” in their approach to the results of the 2020 election.

“That hasn’t changed,” he said. “But also there are profound differences about the future of this country, the future of the Republican Party.”

Asked if he would consider pardoning those who attacked the Capitol, as Mr. Trump has suggested doing, Mr. Pence said, “I have no interest or no intention of pardoning those that assaulted police officers or vandalized our Capitol. They need to be answerable to the law.”

The declaration drew little audible reaction from the audience.

He tied himself to key Trump administration decisions.

Even as Mr. Pence highlighted areas of disagreement with Mr. Trump, he also spoke frequently about their shared time in the White House as he discussed issues as varied as immigration, abortion and the pandemic, illustrating the challenge of running on a record tied so closely to a political rival.

“I couldn’t be more proud to have been vice president in an administration that appointed three of the justices that sent Roe v. Wade to the ash heap of history where it belongs,” he said.

At another point, he said, “I’m proud of everything that we did during our administration to come alongside families and businesses in the midst of the worst pandemic in 100 years.”

He made frequent overtures to evangelical voters.

Mr. Pence, the former governor of Indiana, is a man of deep faith, and his allies see an opening to connect with evangelical voters in Iowa, the leadoff caucus state that is home to many socially conservative voters.

Mr. Pence spoke about his personal faith journey and sprinkled his remarks with references to the Bible. He also emphasized his opposition to abortion rights, pledging that “we will not rest or relent until we restore the sanctity of life to the center of American law in every state in the country.”

“If I have the great privilege to serve as president of the United States, I’ll support the cause of life at every level,” he said, even as he acknowledged that “we have a long way to go to win the hearts and minds of the American people.”

Some Republican presidential candidates have been reluctant to give specifics on their positions regarding abortion policy, or have modulated how they approach it depending on the audience. Mr. Pence seemed eager to discuss the subject, but he faces stiff competition for the voters who are often most moved by the issue. White evangelical voters ultimately became one of Mr. Trump’s most crucial constituencies, and many other candidates, including Gov. Ron DeSantis of Florida, are competing hard to make inroads with those voters as well.

He sounded at times like a pre-Trump Republican.

Mr. Pence invoked former President Ronald Reagan, expressed qualms about spending and made the case for a muscular foreign policy that emphasized American leadership in the world.

Throughout the night, he often sounded like a Republican candidate from the pre-Trump era.

“It’s also disappointing to me that Donald Trump’s position on entitlement reform is identical to Joe Biden’s,” Mr. Pence said as he discussed the social safety net.

He chided both Mr. Trump — and, more obliquely, Mr. DeSantis — for their postures toward Ukraine.

“When Vladimir Putin rolled into Ukraine, the former president called him a genius,” Mr. Pence said. “I know the difference between a genius and a war criminal.”

Swiping at Mr. DeSantis, he said at another point, “I know that some in this debate have called the war in Ukraine a territorial dispute. It’s not.” Mr. DeSantis, who did use that phrase, has since sought to clarify that description, also calling Mr. Putin a war criminal.

And despite his own involvement in the First Step Act, a bipartisan criminal justice overhaul during the Trump administration, Mr. Pence sounded tough-on-crime notes. “I frankly think we need to take a step back from the approach of the First Step Act,” he said.

As the event wound down, Mr. Pence was pressed repeatedly on how he squared casting Mr. Trump as a threat to the Constitution with his promise to support the Republican nominee. Mr. Pence did not answer directly, insisting, “I don’t think Donald Trump’s going to be the nominee.”