4 big takeaways from Day 16 of Trump's hush money trial

The criminal hush money trial of former President Donald Trump reached a crescendo Monday when the state's star witness, former Trump attorney Michael Cohen, testified about his ex-boss directing him to "just take care of" a payment to silence adult film actress Stormy Daniels in the waning days of his 2016 presidential campaign.

Cohen claimed that Trump blessed those negotiations, approved the final deal, and signed off on the reimbursement plan in the final days before his presidential inauguration. Cohen testified that the sole purpose of the scheme was to protect Trump's political fortunes and obscure his role in orchestrating the arrangements.

"Everything required Mr. Trump's sign-off," Cohen said on the stand.

Trump is on trial for allegedly falsifying business records to hide the reimbursement of a hush money payment that Cohen made to Stormy Daniels in order to boost Trump's electoral prospects in the 2016 presidential election. The payment was to buy Daniels' silence about an alleged 2006 sexual encounter with Trump that the former president has steadfastly denied.

Cohen delivered critical testimony for prosecutors from a man who they acknowledge carries significant baggage. But instead of the hyperbolic bombast Cohen often espouses from behind his keyboard, the Michael Cohen jurors met on Monday stayed on message.

The big question now: Will jurors buy it?

Here are four big takeaways from Day 16 of Donald Trump's hush money trial.

'Just do it,' Cohen said Trump told him

Donald Trump's fixer-turned-foe claimed that the then-candidate ordered him to "just do it," referring to the execution of a payment to Stormy Daniels in the waning days of the 2016 campaign.

It was the most direct testimony jurors have heard tethering Trump to the concept of "catch-and-kill" payments to keep unfavorable stories under wraps. Cohen said he solicited feedback from Trump at every point in the process -- from the moment he learned of the allegations to the day payments were executed.

He did so "because everything required Mr. Trump's sign off," Cohen said.

"I wanted to ensure that once again he approved what he was doing, because I required approval from him on all of this," Cohen said.

After hesitating to approve a payment to Daniels, Trump relented, Cohen said, after discussing the matter with "some friends."

"He stated to me that he had spoken to some friends, some individuals, very smart people. It's $130,000. Just pay it. There's no reason to keep this thing out there. Just do it. So he expressed to me, 'Just do it,'" Cohen said.

Daniels' payment was 'all about the campaign,' Cohen said

If Stormy Daniels' story had emerged in the press prior to the 2016 election, Cohen testified that the fallout would have been "catastrophic" for Trump's campaign -- particularly in the wake of the release of the infamous "Access Hollywood" tape in which Trump was heard boasting about grabbing women.

"Women are going to hate me, guys may think it's cool," Cohen recalled Trump telling him, "But this is going to be a disaster for the campaign."

"At the time, Mr. Trump was ... polling very poorly with women," Cohen testified, saying that, coupled with the "Access Hollywood" release, "would have been 'catastrophic' for his electoral prospects."

When the time came to execute a payment to Stormy Daniels, Trump still encouraged Cohen to hold out -- allegedly citing the upcoming Election Day deadline.

"I want you to push it out as long as you can," Cohen said Trump told him about the Daniels story. "Push it out past the election, because if I win, it has no relevance, and if I lose, I don't really care."

In short, Cohen said, "This was all about the campaign."

Cohen stayed on script

Michael Cohen as a witness is a far cry from the Michael Cohen jurors have heard about so far.

Other witnesses have called him a "jerk" and "difficult" -- describing him as a vicious pit bull who would eviscerate anyone who threatened to damage the reputation of his former boss.

But today, in front of the jury, he seemed earnest, morose and -- most importantly for the state -- on script.

Prosecutor Susan Hoffinger tried to back up every word of Cohen's testimony with documentary evidence or prior testimony -- questioning him in a deliberate style of testimony-document-testimony-document -- relying as little as possible on his word alone.

And toward the end of a long day on the stand, Cohen sprinkled in a moment of levity -- perhaps in an effort to endear himself to jurors -- when he acknowledged his reputation as being short-fused.

Asked about his reaction to learning that his bonus at the Trump Organization would be slashed by tens of thousands of dollars, he said, "Even for myself, I was unusually angry," drawing laughter from the gallery.

Cohen's testimony will continue Tuesday

Cohen will return to the witness stand on Tuesday morning, when Hoffinger is scheduled tom continue her direct examination. Prosecutors still need to ask Cohen about the invoices and checks he received -- documents that are central to their case.

At some point on Tuesday, Cohen will face what will likely be a hostile cross-examination from a member of Trump's legal team -- a tete-a-tete that will no doubt test the limits of his temperament.

The state has suggested they could rest their case as soon as this week -- meaning Cohen will be one of their final witnesses.

ABC News' Kendall Ross and Julia Reinstein contributed to this report.