Joe Biden is warning that those “tasked with enforcing the law are abusing their powers”, in a measured critique of the Trump administration.
The comments came a day after Mr Biden declined to respond directly to President Donald Trump’s latest attacks on the Democratic presidential hopeful.
Speaking on Wednesday to Columbia University Law School graduates via video, Mr Biden urged them to “protect the very foundations of democracy”.
“Trust in self-governance. Because right now, it’s under attack,” Mr Biden said.
“The very people tasked with enforcing the rule of law are abusing their powers, protecting their friends, weakening the very principles that make our country work.”
Asked on Tuesday night how he’d respond to the allegations, Biden said: “I don’t want to get down in the mud with these guys.”
Speaking at a Yahoo News virtual town hall on Tuesday, Mr Biden said Mr Trump was trying to distract voters from his inadequate response to the coronavirus pandemic, which has killed more than 90,000 Americans.
Broadly dubbing his allegations Obamagate, Mr Trump has pointed to the legal case of his former national security adviser Michael Flynn, suggesting that the “unmasking” of Mr Flynn’s name as part of legal US surveillance of foreign targets was criminal and motivated by partisan politics.
The “unmasking” of people in surveillance reports is a routine, legal activity in government. The Trump administration made 10,012 such requests in 2019.
But they do do not often become public, and in the Flynn case, Trump supporters point to it as evidence Obama loyalists were out to undermine Mr Trump from the start. The president himself has called it the “biggest political crime and scandal in the history of the USA”.
“This is his pattern. Diversion, diversion, diversion, diversion,” Mr Biden said on Tuesday.
“The greatest crime? I mean, my Lord.”
On Wednesday, a Senate committee led by Wisconsin Republican Ron Johnson will vote on whether to issue a subpoena as part of an investigation into Mr Biden’s son Hunter and his work for a Ukrainian natural gas company. The investigation sprouted from Mr Trump’s impeachment earlier this year.
Over the weekend, Mr Trump’s two adult sons appeared to spread baseless, online conspiracy theories suggesting other criminal activity by Mr Biden. Asked about that on Tuesday, Mr Biden called online posts about the matter “sick”.
“People know me. The good news is the bad news. They know me. They know my faults, they know my talents,” Mr Biden said.
Pointing to his decades in the Senate and eight years as vice president, he said: “It’s hard to lay on me some of the things that are just totally out of sync with anything in my whole life that anyone has ever said about me.”
Also on Tuesday, Mr Biden was asked about Mr Trump’s firing of Steve Linick as the State Department’s inspector general.
Some Republicans have defended the move, arguing that it was within the president’s rights, but Mr Biden and other Democrats say it is part of a larger White House effort to undermine government oversight.
Mr Biden promised not to fire any inspector general should he be elected, saying those positions were “designed to make government honest”.