Julia Roberts gestures during the The Hillary Victory Fund Stronger Together Concert at the St. James Theatre in New York, Oct. 17, 2016.

Magic Johnson posted this photo on Facebook with this caption: "It was so cool showing Hillary Clinton my Lakers trophy room and the 5 championship trophies we won with the "Showtime" Lakers! #imwithher #sheswithus," Aug. 23, 2016.

Katy Perry performs during final night of the Democratic National Convention in Philadelphia, July 28, 2016.

Former NBA star Kareem Abdul-Jabaar speaks during the final day of the Democratic National Convention in Philadelphia, July 28, 2016.

Sheila E performs on the final night of the Democratic National Convention in Philadelphia, July 28, 2016.

Singer-songwriter Carol King performs on the fourth day of the Democratic National Convention, July 28, 2016 in Philadelphia, Pennsylvania.

Actors Ted Danson and Mary Steenburgen speak during the final day of the Democratic National Convention in Philadelphia, July 28, 2016.

Lenny Kravitz performs during the third day of the Democratic National Convention in Philadelphia, July 27, 2016.

Angela Bassett takes the stage at the Democratic National Convention in Philadelphia, July 27, 2016.

Sigourney Weaver speaks during the third day of the Democratic National Convention in Philadelphia, July 27, 2016.

Danny Glover joins supporters of Bernie Sanders delegate Nina Turner for a protest inside the media tent, July 27, 2016.

Actress Meryl Streep addresses the Democratic National Convention at the Wells Fargo Center, July 26, 2016, in Philadelphia, Pennsylvania.

America Fererra, right, and Lena Dunham deliver remarks on the second day of the Democratic National Convention at the Wells Fargo Center, July 26, 2016 in Philadelphia, Pennsylvania.

Actor Tony Goldwyn waves during the second day of the Democratic National Convention at the Wells Fargo Center, July 26, 2016 in Philadelphia, Pennsylvania.

Alicia Keys rehearses before the start of day two of the 2016 Democratic National Convention at Wells Fargo Center, July 26, 2016, in Philadelphia.

Elizabeth Banks speaks during Day 2 of the Democratic National Convention at the Wells Fargo Center in Philadelphia, July 26, 2016.

Eva Longoria waves to the crowd after delivering remarks on the first day of the Democratic National Convention at the Wells Fargo Center, July 25, 2016, in Philadelphia.

US Senator Al Franken, left, and comedian Sarah Silverman share a moment during Day 1 of the Democratic National Convention in Philadelphia, Pennsylvania, July 25, 2016.

Musician Paul Simon performs at the Democratic National Convention at the Wells Fargo Center in Philadelphia, July 25, 2016.

Demi Lavato performs during the first day of the Democratic National Convention in Philadelphia, July 25, 2016.

Actress Susan Sarandon walks on the convention floor during the first day of the Democratic National Convention in Philadelphia, July 25, 2016.

Boyz II Men performs on stage during the opening of the first day of the Democratic National Convention at the Wells Fargo Center, July 25, 2016 in Philadelphia.

Stephen Colbert records a program as preparations are underway ahead of the Democratic National Convention in Philadelphia, July 24, 2016.

Actress and business woman Kimberlin Brown speaks during the second night of the Republican National Convention in Cleveland, July 19, 2016.

Television personality Willie Robertson, of "Duck Dynasty," speaks on the first day of the Republican National Convention on July 18, 2016 at the Quicken Loans Arena in Cleveland, Ohio.

Scott Baio looks over the podium during a sound check before the evening session of the Republican National Convention in Cleveland, Ohio, July 18, 2016.

Actor Antonio Sabato, Jr., speaks during the opening day of the Republican National Convention in Cleveland, July 18, 2016.

Former California Gov. Arnold Schwarzenegger, right, introduces Republican presidential candidate, Ohio Gov. John Kasich, during a campaign rally, March 6, 2016, in Columbus, Ohio.

Julianne Moore speaks during a fundraiser for Democratic presidential candidate Hillary Clinton at Radio City Music Hall, March 2, 2016, in New York City.

Singer Katy Perry raises arms with U.S. Democratic presidential candidate Hillary Clinton at the end of the Hillary Victory Fund "I'm With Her" benefit concert at Radio City Music Hall, March 2, 2016, in New York City.

Jane Sanders, wife of U.S. Democratic presidential candidate Senator Bernie Sanders, is joined by actor Danny Glover at an education forum in Columbia, South Carolina Feb. 23, 2016.

Political commentator Glenn Beck endorses Republican presidential candidate, Sen. Ted Cruz during a rally at the Boys & Girls Club of Truckee Meadows in Reno, Feb. 22, 2016.

Actor/singer Donnie Wahlberg speaks on behalf of Republican presidential candidate Marco Rubio during a rally at the Texas Station Hotel and Casino in Las Vegas, Feb. 21, 2016.

Country music singer Lee Greenwood speaks at a rally for Republican presidential candidate Sen. Marco Rubio, Feb. 21, 2016, in Franklin, Tenn.

Rick Harrison of the television show "Pawn Stars" speaks on behalf of Republican presidential candidate Marco Rubio during a rally at the Texas Station Hotel and Casino in Las Vegas, Feb. 21, 2016.

Actress Susan Sarandon speaks during a rally for Democratic presidential candidate, Sen. Bernie Sanders, Feb. 19, 2016, in Reno.

Actress Eva Longoria speaks ahead of Hillary Clinton, former Secretary of State and 2016 Democratic presidential candidate, during a campaign rally at the Clark County Government Center Amphitheater in Las Vegas, Feb. 19, 2016.

Reality TV's Duck Dynasty star Phil Robertson holds his bible as he endorses Republican presidential candidate Ted Cruz during a campaign rally in Charleston, South Carolina, Feb. 19, 2016.

Actor Justin Long is interviewed at the campaign headquarters of Democratic presidential candidate Sen. Bernie Sanders, Jan. 28, 2016, in Des Moines, Iowa.

Republican presidential candidate Donald Trump shakes hands with former Alaska Gov. Sarah Palin at Hansen Agriculture Student Learning Center at Iowa State University, Jan. 19, 2016, in Ames, Iowa.

Actress and screenwriter Lena Dunham campaigns for U.S. Democratic presidential candidate Hillary Clinton at Eight Seven Central screen printers in Des Moines, Iowa, Jan. 9, 2016.

Actor and producer Seth MacFarlane introduces Democratic presidential candidate Sen. Bernie Sanders during a fundraiser at the Avalon Hollywood, Oct. 14, 2015, in Hollywood, Calif.

Comedian Sarah Silverman introduces Democratic presidential candidate Bernie Sanders at the LA Memorial Sports Arena, Aug. 10, 2015.