Democratic presidential candidate Joe Biden delivers remarks at his primary night election event in Columbia, South Carolina, on February 29, 2020.

With a more than half of the votes counted, Biden led Sanders by about a 44% to 31% margin.

Biden was widely anticipated to walk away from the primary with the bulk of Arizona's 67 pledged delegates. His blowout performance on Super Tuesday earlier this month quashed Sanders' momentum and gave Biden a lead that pollsters increasingly consider to be insurmountable.

Joe Biden will win the Arizona Democratic primary, NBC News projected Tuesday, marking another win for the former vice president.

The Arizona primary went on as scheduled even after Ohio decided to call off its own election amid the novel coronavirus outbreak.

U.S. leaders at every level of government have adopted drastic measures, such as banning large gatherings and forcing restaurants to close their dining rooms, to rein in the spread of the virus.

But Arizona Secretary of State Katie Hobbs told local media outlets Monday that in-person voting would be safe, adding that counties "are implementing common-sense health precautions."

The Arizona State Democratic Party said that roughly 480,000 mail-in ballots had been counted by Tuesday afternoon. That number alone is higher than the total number of votes cast in the 2016 Democratic primary.

Earlier Tuesday, NBC had also projected victories for Biden in Florida and Illinois.

Coming into Tuesday, Biden led Sanders 865 to 714 in the pledged delegate count nationally, according to NBC News.

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