Speaking at a virtual fundraiser Thursday, Joe Biden warned supporters that Donald Trump could use coronavirus as a pretense for delaying or otherwise messing with November’s presidential election. “Mark my words,” Biden said. “I think he is gonna try to kick back the election somehow, come up with some rationale why it can’t be held.”

Trump has not publicly discussed a scenario in which he would delay the election, and—at least legally—he doesn’t have the authority to unilaterally modify it. But the president has repeatedly run roughshod over American political norms in the past, and there is growing fear among Democrats and other Trump critics that he will attempt to do so again—particularly as he tightens his grip on power amid the COVID-19 pandemic. “My concern is that in the age of Trump that other governors might think, or that the president might ask, for a delay in the November election based on something, perhaps this, perhaps something else,” Ohio Senator Sherrod Brown said last month, after his home state postponed its primary.

The president’s autocratic maneuvers have so far focused on purging his government of oversight, but he may soon have incentive to play games with the 2020 election; a parade of recent polls show him trailing Biden, including among the older voters that help form the core of his base. His re-election campaign’s internal polling has been similarly ominous, showing worsening numbers in swing states—something that’s weighed on him in recent weeks. According to the New York Times, allies have described Trump as being “unsettled and worried about losing the election” in recent conversations with him as he spends his time largely confined to the White House, glued to his television save for the two hours each day he gets in the briefing room sparring with reporters and casually suggesting people mainline Lysol. “He’s frustrated,” outside adviser Stephen Moore told the Times.

Whatever obstacles Trump would face should Biden’s prediction come true, Democrats have good reason to be concerned. The guardrails that should have prevented Trump from, say, attempting to strong-arm the president of Ukraine into meddling in the 2020 election failed to contain him — thanks to the Republicans who acquitted him of impeachment earlier this year. The courts, which Trump and Mitch McConnell have spent the last three years stacking with conservatives, have been similarly friendly to the president and his party; conservative justices have already shown themselves willing to go along with Republicans’ obvious voter suppression efforts. There’s real reason to question whether the checks on Trump’s power will actually be enforced should he play games in November—or if the president, who has repeatedly lied about mass voter fraud contributing to his 2016 popular vote loss, were to question the results of the election if he loses. “We have to figure out how we are going to conduct a full and fair and safe election in November,” Biden said Thursday.

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