Senator Barack Obama (D-IL) (R) stands in front of Senator Hillary Clinton (D-NY) as they arrive for U.S. President George W. Bush's annual State of the Union speech to a joint session of Congress at the U.S. Capitol in Washington in this January 23, 2007 file photo. Hillary Clinton announced her second run for the presidency on April 12, 2015 starting her campaign as the Democrats' best hope of fending off a crowded field of lesser-known Republican rivals and retaining the White House. (Photo by Larry Downing/Reuters)

Lightning from a tornadic thunderstorm passing over Clearwater, Kansas strikes at an open field May 19, 2013. A massive storm front swept north through the central United States on Sunday, hammering the region with fist-sized hail, blinding rain and tornadoes, including a half-mile wide twister that struck near Oklahoma City. News reports said at least one person had died. (Photo by Gene Blevins/Reuters)

A reveler takes part of the Light Festival parade in San Jose, Costa Rica on December 14, 2019. (Photo by Ezequiel Becerra/AFP Photo)

A couple shares a light moment in a Mass Transit Railway (MTR) subway train in Hong Kong, China on August 28, 2019. (Photo by Anushree Fadnavis/Reuters)

Former Vice President Joe Biden, 2020 Democratic presidential candidate, right, watches as his wife Jill Biden, center, blocks a protester from arriving on stage during an primary night rally in the Baldwin Hills neighborhood of Los Angeles, California, U.S., on Tuesday, March 3, 2020. The biggest day of the presidential primary calendar will define the nomination fight for Bernie Sanders and Biden and determine whether Michael Bloomberg and Elizabeth Warren have a rationale for carrying on their campaigns. (Photo by Patrick T. Fallon/Bloomberg via Getty Images)

Visitors, wearing face masks, enter the Disneyland theme park in Shanghai as it reopened, Monday, May 11, 2020. Visits will be limited initially and must be booked in advance, and the company said it will increase cleaning and require social distancing in lines for the various attractions. (Photo by Sam McNeil/AP Photo)

A Palestinian man demonstrates his parkour skills on a beach as the coronavirus disease (COVID-19) restrictions ease in Gaza City on July 10, 2020. (Photo by Mohammed Salem/Reuters)

People try to board an overcrowded passenger train as they travel home to celebrate Eid al-Fitr festival, which marks the end of the Muslim holy fasting month of Ramadan, at a railway station in Dhaka, Bangladesh, July 5, 2016. (Photo by Adnan Abidi/Reuters)