Trump attacks Mueller's investigation on eve of his testimony to Congress

The president lashed out at Mueller in a speech to high school students.

In a 79-minute campaign rally-like speech to conservative high school students, Trump said "It goes on for years and years. No collusion, no obstruction – that’s not good enough – let’s go more. Forty million dollars, they interviewed 500 people and they got nothing!"

"I saw Mueller is set to testify again. How many times? Two and a half years. And actually, it started practically from the time I came down on the escalator they said you know, he's got good numbers," Trump said. "We better start looking at him right away, maybe he's dealing with a foreign country."

Trump was referring to his ride down an escalator at Trump Tower in New York in June 2015 when he announced his run for president.

"They did a report and there was no obstruction after looking at it, our great attorney general read it, he's a total professional," Trump said. "He said, there's nothing here, there's no obstruction. So, they referenced no obstruction. So, you have no collusion, no obstruction, and yet it goes on."

In his classic, greatest-hits style political speech, the president ran over 45 minutes past his scheduled speaking time at the Turning Point USA Teen Action Summit in Washington, D.C.

Turning Point USA is a conservative non-profit organization that targets students at college campuses and high schools across the country and is led by Charlie Kirk, a political activist. The crowd was replete with red MAGA hats, and some teens had signs that read, "Hate U.S. cuz they ain’t U.S.” an apparent to the four Democratic members of Congress, all American citizens and women of color -- three of whom were born in the U.S. -- who Trump tweeted should "go back" to the countries they came from.