Speaking out at a stop on the campaign trail, former vice president Joe Biden pledged not to attack his 20-plus rivals for the Democratic presidential nomination.

“You will never hear me speak ill of another Democratic candidate, and there’s a really simple reason for that,” Biden said. “We have to be in a position, whoever the nominee is, to be able to win. And there’s also a second thing. What will may disappoint you: I’m not going to get down in the mud wrestling with [Donald Trump]. I’m not going to stoop to his level. I’m not going to engage in the name-calling, but I’m just going to — someone said ‘Give him hell, Joe.’ Well, my Grandpa Finnegan used to say, quote Harry Truman, he’d say ‘Harry, give them hell.’ He said, ‘No, I’m not going to give them hell, I’m just going to tell them the truth and let them think it’s hell.'”

Biden also made remarks about what Trump and members of his administration have been doing in response to special counsel Robert Mueller completing his investigation into Russian Interference in the 2016 election and potential Trump campaign involvement.

“So there’s a lot going on here. You’re absolutely right. And now they have an investigation of the investigators who were investigating whether or not Vladimir Putin and the Russians engaged in trying to affect our lives. Give me a break, gosh almighty!” Biden exclaimed.

Biden also defended his work as a senator in the early 1990s on the major Crime Bill approved under President Bill Clinton. Today the Crime Bill is often criticized, particularly on the left, for beginning a trend of mass incarceration particularly among African Americans.

“Folks, let’s get something straight. 92 out of every 100 prisoners that are behind bars are in a state prison, not a federal prison. This idea that the crime bill generated mass incarceration, it did not generate mass incarceration. … Secondly, the court, I made sure there was a set-up in that law that said there were no more mandatory [minimum sentences], except two that I had to accept. One was that President Clinton wanted three strikes and you’re out, and was part of this entire bill that included the Violence Against Women Act, included the gun control efforts … ” Biden said. “But here’s the deal. What happened is, the mass incarceration occurred by the states setting mandatory sentences. What happened was, if you go back and look, the [Congressional] Black Caucus supported the bill.”

In a separate interview, Biden criticized attempts by Trump and his personal attorney, Rudolph Giuliani, to dig up dirt on Biden’s son, Hunter, work for a gas company in Ukraine as a “personal attack.”

“It’s hard for me to comment on Rudy Giuliani. I don’t think I will because my Irish may come up. It is a personal attack. I expect that from Rudy Giuliani and the president,” Biden said. “It’s not been one scintilla of evidence that my son ever interfered and I got involved in anything other than doing the job I was supposed to do.”