Former Vice President Joe Biden on Thursday mocked President Trump's habit of bragging about his intelligence in one of his most direct criticisms of the President's possible bid for the White House in 2020.

In a broad-based Washington speech on labor issues and economic policies, Biden told the audience that as a student he did well on standardized tests, he quipped, "I'm clearly not as smart as Trump, the world's smartest man in the world I have a relatively high IQ. "

Trump in January praised himself as a "very stable genius" and often vaunted long before his 2016 presidential run, his IQ is "one of the highest."

The speech on Thursday was the third appearance of Biden on the national stage in recent weeks. Late last month, he gave a veiled reprimand from Trump in an emotional eulogy for the late Senator John McCain (R-Ariz.) In Phoenix. He also criticized Trump, without naming him in a glowing speech for a Democratic House candidate in New Jersey last week.

Economic and labor market policy was the focus of the "Building an America of Higher Wages" summit, and Biden spoke at length about the issue, making himself the champion of the middle class and calling for measures such as non-competition for low-salaried employees.

But politics – and Trump – was clear in his mind.

When he began his speech, Biden told of his father's favorite saying, "Do not compare me to the Almighty. Compare me to the alternative."

"I think that's the only reason I'm okay these days – the alternative," Biden said, to laugh at the crowd.

He went on to do something that seemed to be a trumpet to Trump's tweets when he falsely accused the Democrats on Thursday of inflaming the number of deaths attributed to Hurricane Maria in Puerto Rico last year.

"By the way, there are no problems in America," Biden said dryly. "Everyone's fine, things are fair and decent, and nobody died in Puerto Rico."

Trump also distinguished himself from Biden's comments on the minimum wage, which, he claimed, are not just a topic of the economy, but also how open-minded the public is to populist and nationalist appeals.

"What we're talking about here today, people who are able to earn a decent wage, is the ultimate antidote to all this stupidity that goes on with that false populism and naked nationalism just being announced," Biden said.

He argued that people in difficult economic times are more susceptible to the rhetoric of "charlatans coming along, trying to find a reason for those who deal with them to be responsible for the" other " on this black man or black woman. "

"It has made itself felt here in the United States," Biden said.

Elsewhere in his speech, Biden criticized non-competition clauses for hourly workers, such as sandwich makers at Jimmy Johns, who postponed the use of such clauses after reaching an agreement in 2016.

"What the hell is that?" Biden asked. "What can it be, except to suppress wages, what other justification can there be in it?"

He also criticized the practice of workers forced to sign contracts that required compulsory arbitration in case of dispute, arguing that "people do not have to sign their rights to get a job".

"If a woman is sexually harassed by her boss, should she not be able to bring her case to court to be heard by an impartial judge and jury?" Said Biden. "I'm not saying that all employers are evil, they are not, but if they violate fundamental rights, you should be able to take a step forward."

The almost one-hour speech showed several campaign-like flourishes. At some point Biden looked up and saw someone in the room picking up a sign.

Do you speak too long? "Biden said before noticing that the owner encouraged him to make another public offer. "Oh, run Joe!"

Biden later left the podium and began to walk around the front of the room, attracting the crowd as if he was at a city hall meeting. After a few moments, an organizer gave him a microphone and Biden had obviously decided that he had exceeded his greeting.

"Thank you all, I'm damned out of here," he said.