Mike Pence goes after Donald Trump in CNN Iowa town hall. Here's what he said.

WASHINGTON - Mike Pence capped his first day as a 2024 presidential candidate by again going straight at the biggest issue of the Republican race: Donald Trump, the man who made him vice president.

Echoing comments he made throughout his opening day, Pence used a CNN town hall in Iowa to hit Trump over federal spending and entitlement reform, Vladimir Putin, and, most especially, Trump's actions prior to the insurrection of Jan. 6, 2021.

"I said today that I felt that he was asking me to choose between him and the Constitution," Pence said of his former patron Trump. "I chose the Constitution, and I always will."

As for current investigations, Pence said he hopes the Justice Department does not indict Trump over the handling of classified information because it would be "terribly divisive." He lamented the March indictment of Trump in New York over a hush money case.

The former vice president also punted on a question about whether he would pardon Trump if his former president is convicted in one or more of the investigations against him.

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"I don't want to speak about hypotheticals," Pence said, adding in a joking manner: "I'm not sure I'm going to be elected president of the United States."

Some Republicans mocked Pence for his take on Trump’s legal troubles. Another presidential candidate, Asa Hutchinson, tweeted that “the @GOP should clarify that there is no pledge to support a nominee if they are found guilty of espionage or a serious felony.”

'I don't think he's going to be the nominee'

Pence, who is in single digits in most polls, preferred to attack President Joe Biden and the Democrats. He also made clear that Trump's legacy will be a big part of his longshot presidential campaign.

The former vice president also said he would back whoever the Republicans nominate in 2024, even if it's Trump. Pence said he plans to be the nominee and he hopes Trump "comes around" on their differences, especially over Jan. 6.

Regarding Trump, Pence said: "I don't think he's going to be the nominee."

A requirement to get on the debate stage is that all candidates have to agree to support the eventual GOP nominee.

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No comment from Trump

Trump did not comment publicly on Pence Wednesday, while allies took a low-key and skeptical approach.

Karoline Leavitt, spokeswoman for the political action committee known as Make America Great Again, said Pence jumped into the race because of the perceived weakness of fellow Trump challenger Ron DeSantis.

"Mike Pence’s entrance into the race caps off another bad week for Ron DeSantis’ faltering campaign," Leavitt said, "but the question most GOP voters are asking themselves about Pence’s candidacy is ‘Why?'"

This is not 2016

This is quite a change from the 2016 presidential cycle, when Republican opponents of Trump tended to attack each other rather than risk alienating Trump's large base of voters.

This time around, Trump is taking heat from an increasing number of challengers, including DeSantis, Chris Christie, and now Pence.

"It's time," Pence told CBS News after his announcement speech. "It's time."

Jan. 6 dispute

In his speech, subsequent interviews and his CNN town hall, Pence made his most critical comments about Trump and his attempts to overthrow his 2020 election loss to Biden.

Trump demanded that Pence, in his role as president of the Senate, throw out electoral votes for Biden and essentially re-elect Trump to the White House. Pence said he had no legal authority to do that and that Trump violated his oath of office in asking.

Trump is under investigation by a special counsel for actions leading up to Jan. 6, as well as the classified documents case.

The Jan. 6 investigation generated another unique aspect of Pence's candidacy: He once testified before a grand jury about the former president and front-runner for the 2024 GOP nomination.

Pence also told CNN he has no intention of pardoning anybody who vandalized the U.S. Capitol on Jan. 6, 2021, a subject that Trump has broached.

The abortion issue

Asked about the issue during the CNN town hall, Pence said he would continue to fight for the end of abortion. He did not mention his emerging differences with Trump on the issue that is important to conservative religious voters in Iowa and other states.

While he said he opposes abortion, Trump has also said his party may be going too far in seeking bans on the practice. The issue is hurting Republican candidates, he said, and contributed to poor showings by the GOP in the 2022 elections.

Earlier in the day, during his announcement speech, Pence said Trump and "others in this race are retreating from the cause of the unborn."

Russia and Putin

Pence has also hit Trump on foreign policy issues, particularly Russia's invasion of Ukraine.

Trump has said he could settle the Russia-Ukraine war in a single day, presumably by offering concessions to Russian dictator Vladimir Putin.

On CNN, Pence said Putin should not be rewarded for aggression. He also repeated his past criticism of Trump for once describing the Russian leader as "a genius."

"I know the difference between a genius and a war criminal," Pence told the CNN town hall.

Spending, Social Security, and Medicare

Federal spending and entitlements also provided a dividing line between Pence and Trump.

Pence said the government cannot address its debt crisis without making changes to Social Security, Medicare, and other entitlement programs.

On CNN, Pence said it was "disappointing" that Trump has the same view of entitlements as Biden.

"Their policy is insolvency," Pence said.

Trump and other Republicans said reduced spending should not come at the expense of senior citizens who have earned their benefits.

Escalating criticism of Trump

As Pence researched the prospects of a presidential campaign over the past year-and-a-half, many Trump voters said they are still angry at him for not helping reverse the 2020 election.

Trump critics, meanwhile, hold Pence's past fealty to the ex-president against him.

Amid this squeeze, Pence gradually escalated his criticism of Trump, but confined it mostly to the Jan. 6. In February of last year, Pence said Trump was "wrong" to demand the overturning of the election.

At a press dinner this past March, Pence expanded his misgivings about Jan. 6: "I had no right to overturn the election. And his reckless words endangered my family and everyone at the Capitol that day. And I know that history will hold Donald Trump accountable.”

On announcement day, Pence expanded critique to issue like abortion, entitlements, and Putin.

Single digits

Pence has his work cut out for him, if polls are any guide.

The former vice president pulled only 4% in a Reuters/Ipsos poll last month, far behind Trump at 31%.

A number of polls have shown a lack of regard for Pence among Trump backers, and a lack of support from Republicans who oppose Trump.

"He's not seen as an alternative," said Clifford Young, president of U.S. Public Affairs at Ipsos. "He's in the worst place possible."