Lea Gaughan, 86, writes her signature on a screen with a popsicle stick while receiving her ballot at Sonoma Elementary School during the primary election in Las Cruces, New Mexico, U.S., June 2, 2020.

An election official holds an individually bagged "I Voted" sticker on D.C.'s primary election day, following the outbreak of the coronavirus disease (COVID-19), in Washington, U.S., June 2, 2020.

A woman reaches in to cast her ballot for Maryland's primary election at a drop box in Rockville, Maryland, U.S., June 2, 2020.

Caleb Kirkland, (R) gets his ballot from machine judge Pio Sancez during the primary election at Sonoma Elementary School in Las Cruces, New Mexico, U.S., June 2, 2020.

People wearing masks to prevent the spread of coronavirus disease (COVID-19) wait to vote in the primary election in Philadelphia, Pennsylvania, U.S., June 2, 2020.

Election worker Gisela Alberg cleans a voting booth at Sonoma Elementary School during the primary election in Las Cruces, New Mexico, U.S., June 2, 2020. New Mexico Republicans sued to block efforts to hold a mail-in statewide election which was proposed amid fears of the COVID-19 pandemic.

Nancy Miranda wears a campaign-branded mask as she holds a poster near a polling station on D.C.'s primary election day, following the outbreak of the coronavirus disease (COVID-19), in Washington, U.S., June 2, 2020.

A woman wearing a mask to prevent the spread of coronavirus disease (COVID-19) walks from a voting booth during primary election voting in Philadelphia, Pennsylvania, U.S., June 2, 2020.

A poll worker wearing a mask to prevent the spread of coronavirus disease (COVID-19) gives a voter her ballot during the primary election voting in Philadelphia, Pennsylvania, U.S., June 2, 2020.

A voter sanitizes their hands behind a plastic shield before checking in to a polling location on D.C.'s primary election day, following the outbreak of the coronavirus disease (COVID-19), in Washington, U.S., June 2, 2020.

A bottle of hand sanitizer to prevent the spread of coronavirus disease (COVID-19) sits next to voting stickers at a polling station during primary election voting in Philadelphia, Pennsylvania, U.S., June 2, 2020.

Voter Brian Taylor prepares to cast his ballot in the Democratic primary in Philadelphia, Pennsylvania, U.S., June 2, 2020. The city has provided masks, gloves, and hand sanitizers to poll workers and voters because of COVID-19, and has also drastically decreased the number of polling places in use to accommodate the majority of voters who are expected to cast their vote by mail.

Jacob Graff, 19, (L) casts his first ballot with his father Benjamin while wearing a mask to prevent the spread of coronavirus disease (COVID-19) in Philadelphia, Pennsylvania, U.S., June 2, 2020.

Voters prepare to cast their ballot in the Democratic primary in Philadelphia, Pennsylvania, U.S., June 2, 2020. The city has provided masks, gloves, and hand sanitizers to poll workers and voters because of COVID-19, and has also drastically decreased the number of polling places in use to accommodate the majority of voters who are expected to cast their vote by mail.

A voter checks in behind a plastic shield before checking in to a polling location, on D.C.'s primary election day, following the outbreak of the coronavirus disease (COVID-19), in Washington, U.S., June 2, 2020.

Voters Linda Petro and Bernice Sawyer (left) prepare to cast their ballot in the Democratic primary in Philadelphia, Pennsylvania, U.S., June 2, 2020. The city has provided masks, gloves, and hand sanitizers to poll workers and voters because of COVID-19, and has also drastically decreased the number of polling places in use to accommodate the majority of voters who are expected to cast their vote by mail.

Voters wearing masks line up with social distance to cast their ballot in the primary election at Sonoma Elementary School in Las Cruces, New Mexico, U.S., June 2, 2020. New Mexico Republicans sued to block efforts to hold a mail-in statewide election which was proposed amid fears of the COVID-19 pandemic.

A voter walks past tape calling for social distancing to prevent the spread of coronavirus disease (COVID-19) at a polling station during the primary election voting in Philadelphia, Pennsylvania, U.S., June 2, 2020.