Trump's N.Y. hush money trial begins. Here's what you missed the first day.

Donald Trump — now a former president on trial — has sought to turn his legal peril into a boost for his presidential campaign, animating his supporters and attempting to sow doubt about the motives of his opponents.

But facing 34 counts of felony charges, Trump argued on the historic first day of his New York hush money trial that he is the victim of a criminal justice system weaponized against him.

He called it “an assault” on the nation. And as the presumptive Republican nominee for president, he repeatedly attacked the prosecution for waging "election interference."

It is “why I’m very proud to be here,” Trump said.

Trump intends to be involved at every level to the extent possible, from court conferences to the jury selection process, his defense attorney Todd Blanche said.

“President Trump wants to be present at everything,” Blanche said.

For much of the day, Trump was seated at the defense table flanked by his attorneys. At times, his voice could be heard in the back of the courtroom, though not what he was saying. At other moments, Trump shut his eyes — drawing speculation about whether he was still awake or just lost in thought.

Here is what happened during Monday's proceedings:

Jury selection

About 500 New Yorkers arrived for Day 1 of Trump’s criminal trial over hush money payments for a process that will take days — and could take weeks — as the court works to weed out jurors who could be swayed by strong biases or stealth jurors who may be hiding theirs.

Questions like “Are you, or have you ever been a member of groups like the Oath Keepers, or ‘3 percenters?’” referring to another far-right group, are used to narrow the pool. Other questions, say about a prospective juror’s hobbies or educational background, are a less overtly political way to gauge a juror's potential fairness.

By the time the judge presiding over the case, Juan Merchan, said he was ready to begin jury selection, about 200 Manhattanites were in the courthouse waiting to find out whether they would be selected.

Trump was seated at the defense table as the first batch of 96 jurors was brought into the courtroom, filling the pews behind him. Their names and those of any other prospective jurors must be kept secret — except to the defense and the prosecution.

Speaking to his lawyer, Trump gestured with his hands as Merchan discussed the handling of jury pool names. The defense and the prosecution each received copies of the potential jurors' names, which Merchan has said cannot in any way be duplicated and must be returned to the court. They also received copies of juror numbers.

It can be an intimidating process. More than half of prospective jurors from the first batch of 96 — at least 50 — were excused after they said they could not be fair and impartial. Nine more were excused when Merchan asked them whether there were other reasons for which they could not serve.

Half of the remaining pool of about 34 were called to start voir dire, in which they would be queried by both parties, including about their media consumption habits. Trump appeared to track the process closely, reading along as it got underway.

Witnesses

Trump allegedly told his former attorney and fixer Michael Cohen to send porn star Stormy Daniels hush money during his run for president in 2016, a claim that is at the center of the charges in this case. Prosecutors say that was part of a scheme to suppress negative stories about Trump in the lead-up to Election Day, which they argue should be charged as election interference.

Trump has denied the charges, but prosecutors say that he is going after those he claims are attacking him, including key witnesses in the case — and that he has made that a tactic.

“The defendant himself has publicly embraced the public strategy of going after his perceived enemies,” prosecutor Joshua Steinglass said.

Defending Trump, Blanche said he is the one facing attack by witnesses against him.

“He is responding to salacious, repeated, vehement attacks by these witnesses,” Blanche said.

Inside the courtroom, large monitors showed a closed-circuit feed of the judge and the defense and prosecution tables.

In court, Merchan read through a list of possible witnesses, name-checking members of Trump’s family, including his children Donald Trump Jr. and Ivanka Trump; his wife, Melania; and his son-in-law Jared Kushner. Merchan named longtime associates of Trump, such as Kellyanne Conway, Dan Scavino and Rudy Giuliani; his bodyguard Keith Schiller; and White House aides John McEntee, Hope Hicks and Madeleine Westerhout.

The risk of jail time

Trump, who must be in the courtroom for every day of the trial, has decried the case as a “persecution like never before,” and on Monday, standing outside the courtroom, he argued that it constitutes “an attack on a political opponent.”

Merchan warned Trump that he risks jail time if he disrupts the trial, which would continue in his absence. Already, prosecutors are seeking to impose thousands of dollars in fines for three alleged violations of a gag order, including Monday morning’s.

If Trump fails to show up, a warrant could be issued for his arrest, an obligation that his campaign lambasted as “Banana Republic tactics.”

It is a “case that should never have been brought,” Trump said.

The trial could drag on for weeks, rerouting to New York a presidential campaign that otherwise could be making overtures to voters in some of the states Trump will need to win in November.

He resumed his criticism as the day came to a close, airing among his grievances a ruling by Merchan barring him from attending arguments at the Supreme Court about the question of whether he is entitled to presidential immunity, which he has raised in another of his criminal cases.

“This is about election interference,” Trump said outside the courtroom.

He lashed out on social media, as well, posting articles on Truth Social that denounced the case as “politically driven” and reposting support from a variety of defenders.

As in his other cases, Trump did not shy away from leveraging his latest legal entanglement for a campaign boost.

A fundraising text message went out at the same time, thundering that he would “never surrender.” Trump’s fundraising has surged during moments of potential legal peril, delivering him much-needed financial and messaging boosts as he navigates the challenges of another White House run.

On the first day of his trial, Trump made the court case his pitch.

“I JUST STORMED OUT OF COURT!” he hammered in the message. “They think I’m finished but I’LL NEVER SURRENDER.”

Admissible or not?

As prosecutors played evidence to the court that Trump’s lawyers argued should not be admissible, Trump, seated at the defense table, watched along on a monitor. That included an excerpt from Trump’s deposition in the E. Jean Carroll case in which he defended his lewd comments on an "Access Hollywood" tape that surfaced in the lead-up to the 2016 presidential election, as well as remarks from at a campaign rally late in that election cycle, when he showed concern over what he said were false accusations.

Jurors should know Trump’s exact words, prosecutors argued. They also displayed tweets they said were evidence of Trump’s pressure campaign on Cohen not to cooperate with prosecutors.

Merchan reinforced a ruling that the "Access Hollywood" could not be played to the jury — though it could be discussed — and barred prosecutors from introducing the deposition video about it.

When prosecutors asked to introduce evidence about allegations of Trump’s coordination with the National Enquirer to “catch and kill” stories potentially devastating to his 2016 campaign, Trump’s attorney dismissed the request as a “sideshow.” Merchan ruled that the evidence would be admissible.

In a win for the defense, Merchan denied prosecutors’ request to bring in other allegations against Trump of sexual assault. “Complete hearsay,” he called them.

Merchan gave Trump a 24-hour deadline to enter final exhibits into evidence. “You have 24 hours,” he ordered. "Whatever you don’t identify in the next 24 hours, you will be precluded from using.”

What's next?

Merchan said he would wait to hear arguments next week about whether Trump violated his gag order by posting social media comments about witnesses in the case.

Last week, Trump said he would "absolutely" testify in the trial, and Tuesday, Merchan will conduct a hearing designed to ensure that the decision is well-informed. Known as a Sandoval hearing, it will delve into what could come up under cross-examination when Trump is on the witness stand.

Merchan rejected a request that Trump be excused April 25 to attend the Supreme Court arguments about the immunity claim.

In another of his cases, Trump has argued that he should be able to push back two filing deadlines on the basis that his attorneys will be overloaded with the New York trial over the coming six weeks. The request shows how the trial has become the latest opportunity for Trump's team to stall forward momentum on the legal charges against him.

This article was originally published on NBCNews.com