August 20, 2020

As Biden prepared to accept Democratic nomination for president, a furious Trump took to Twitter

WATCH: DNC 2020: Night 4 key moments

As Joe Biden prepared to take the most important step in his political career thus far, on Thursday, President Donald Trump was having an entirely different kind of day.

Trump's former strategist, Steve Bannon, was indicted for fraud Thursday, and court documents show that New York prosecutors are working to reinstate an indictment against another Trump associate: his former campaign chairman, Paul Manafort, for mortgage fraud.

Earlier on Thursday, a federal judge rejected Trump's motion to block the Manhattan district attorney from obtaining his tax returns.

To add to Trump's grief, more than 70 former Republican national security officials, including some former members of the Trump administration, came out in support of Biden.

MORE: More than 70 Republican former national security officials come out in support of Biden

Minutes before Biden was set to accept the Democratic nomination for president, Trump was on Twitter, taking aim at the former vice president and at mail-in voting.

Carolyn Kaster/AP
Supporters rally outside the venue where Democratic presidential candidate former Vice President Joe Biden will speak, during the final day of the Democratic National Convention, Aug. 20, 2020, at the Chase Center in Wilmington, Del.

Trump's claim he stands for "law and order" comes on the same day that his former campaign CEO and chief strategist in the White House, Steve Bannon, was arrested and charged for defrauding donors in an online scheme.

MORE: Prosecutors looking to reinstate indictment against former Trump campaign chairman Paul Manafort for mortgage fraud

Trump also argued that Biden "excuses" and "allows crime," though Biden, in response to the violent protests going on around America, has taken a firm stance. "We do need to hold those who violate the law accountable," he recently said.

"We should never let what's done in a march for equal rights overcome what the reason for the march is," Biden said. "And that's what these folks are doing. And they should be arrested -- found, arrested and tried."

Evan Vucci/AP
President Donald Trump holds a pizza during a visit to Arcaro and Genell restaurant after speaking at a campaign event, Aug. 20, 2020, in Old Forge, Pa.

Trump continued tweeting Thursday, claiming Democrats are demanding mail-in ballots because enthusiasm for "Slow Joe Biden" was lagging and Democrats are "concerned very few people will turn out to vote."

MORE: Former Trump strategist Steve Bannon indicted for fraud as part of crowdfunding campaign to build border wall

Trump did not mention the COVID-19 pandemic's role in the desire for mail-in voting. The virus has now killed more than 170,000 Americans.

As the final night of the Democratic National Convention kicked off, he asked why Democrats are against voter identification, yet "must have an ID card" to get into the DNC. The convention this week has been entirely virtual, and has been streamed publicly to anyone who wishes to participate online.