Biden's victory over Trump in 2020 was not particularly close. He won the Electoral College with 306 votes to Trump's 232, and the popular vote by more than seven million ballots.

Because the Electoral College ultimately determines the presidency, the race was decided by a few battleground states. Many of those states conducted recounts or thorough reviews of the results, all of which confirmed Biden's victory.

In Arizona, a six-month review of ballots in the state's largest county, Maricopa, that was commissioned by Republican state legislators not only affirmed Biden's victory but determined that he should have won by 306 more votes than the officially certified statewide margin of 10,457.

In Georgia, where Trump was recently indicted for his efforts to overturn the 2020 result there, state officials led by both a Republican governor and secretary of state recertified Biden's win after conducting three statewide counts. The final official recount narrowed Biden's victory in the state from just shy of 13,000 votes to just shy of 12,000 votes.

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In Michigan, a committee led by Republican state senators concluded there was no widespread or systematic fraud in the state in 2020 after conducting a monthslong investigation. Michigan, where Biden defeated Trump by almost 155,000 votes, or 2.8 percentage points, was less competitive compared with other battleground states, although the result in Wayne County, home of Detroit, was targeted by Trump and his supporters with unfounded voter fraud claims, as were key urban jurisdictions across the country.

In Nevada, the then-secretary of state, Republican Barbara Cegavske, and her office reviewed tens of thousands of allegations of possible voter fraud identified by the Nevada Republican Party but found that almost all were based on incomplete information and a lack of understanding of the state's voting and registration procedures.

For example, Cegavske's investigation found that of 1,506 alleged instances of ballots being cast in the name of deceased individuals, only 10 warranted further investigation by law enforcement. Similarly, 10 out of 1,778 allegations of double-voting called for further investigation. Biden won Nevada by 33,596 votes, or 2.4 percentage points.

In Pennsylvania, the final certified results had Biden with an 80,555-vote margin over Trump, or 1.2 percentage points. Efforts to overturn Pennsylvania's election failed in state and federal courts, while no prosecutor, judge or election official in Pennsylvania has raised a concern about widespread fraud.

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State Republicans continue to attempt their own review of the 2020 results, but that effort has been tied up in the courts and Democrats have called it a "partisan fishing expedition."

In Wisconsin, a recount slightly improved Biden's victory over Trump by 87 votes, increasing Biden's statewide lead to 20,682, or 0.6 percentage points. A nonpartisan audit that concluded a year after the election made recommendations on how to improve future elections in Wisconsin but did not uncover evidence of widespread voter fraud in the state, leading the Republican co-chair of the audit committee to declare that "the election was largely safe and secure."

The state's Assembly speaker, a Republican, ordered a separate review, which a state judge said found "absolutely no evidence of election fraud."