US President Barack Obama waves as he walks to Marine One prior to departure from the South Lawn of the White House in Washington, DC, June 23, 2016, en route to California and Washington. / AFP PHOTO / SAUL LOEBSAUL LOEB/AFP/Getty Images

US President Barack Obama walks to Marine One prior to departure from the South Lawn of the White House in Washington, DC, June 23, 2016, en route to California and Washington. / AFP PHOTO / SAUL LOEBSAUL LOEB/AFP/Getty Images

Protesters hold up signs and flags to show solidarity with House Democrats after they staged a sit in over gun-control laws on Capitol Hill in Washington, DC on June 23. 2016. Democratic lawmakers pushing for tougher US gun control laws after the Orlando nightclub massacre ended a stunning 24-hour sit-in at Congress. / AFP PHOTO / Andrew CABALLERO-REYNOLDSANDREW CABALLERO-REYNOLDS/AFP/Getty Images

Representative Jerrold Nadler (D-NY)speaks with supporters after a sit-in over gun-control laws with other House Democrats on Capitol Hill in Washington, DC on June 23. 2016. Democratic lawmakers pushing for tougher US gun control laws after the Orlando nightclub massacre ended a stunning 24-hour sit-in at Congress. / AFP PHOTO / Andrew CABALLERO-REYNOLDSANDREW CABALLERO-REYNOLDS/AFP/Getty Images

A protester holds up a sign to show solidarity with House Democrats after they staged a sit in over gun-control laws on Capitol Hill in Washington, DC on June 23. 2016. Democratic lawmakers pushing for tougher US gun control laws after the Orlando nightclub massacre ended a stunning 24-hour sit-in at Congress. / AFP PHOTO / Andrew CABALLERO-REYNOLDSANDREW CABALLERO-REYNOLDS/AFP/Getty Images

Protesters hold up signs and flags to show solidarity with House Democrats after they staged a sit in over gun-control laws on Capitol Hill in Washington, DC on June 23. 2016 Democratic lawmakers pushing for tougher US gun control laws after the Orlando nightclub massacre ended a stunning 24-hour sit-in at Congress. / AFP PHOTO / Andrew CABALLERO-REYNOLDSANDREW CABALLERO-REYNOLDS/AFP/Getty Images

WASHINGTON, DC - JUNE 23: (L-R) Reps. John Lewis (D-GA), James Clyburn (D-SC), Maxine Waters (D-CA) and Charles Rangel, (D-NY) speak with supporters outside the U.S. Capitol building June 23, 2016 in Washington, DC. Democratic House members ended their overnight House floor sit-in trying to force a vote on gun control legislation. (Photo by Allison Shelley/Getty Images)

WASHINGTON, DC - JUNE 23: Rep. John Lewis (D-GA), left, Minority Leader Nancy Pelosi (D-CA), center, and Charles Rangel, (D-NY), right, speak with supporters outside the U.S. Capitol building June 23, 2016 in Washington, DC. Democratic House members ended their overnight House floor sit-in trying to force a vote on gun control legislation. (Photo by Allison Shelley/Getty Images)