Thousands of atheists gather for 'Reason Rally' in Washington, D.C.

WASHINGTON, June 5 (UPI) -- Reason for Rally 2016 drew several thousand atheists and supporters at the National Mall on Saturday in a quest to show that those with non-religious beliefs can be a political force in the upcoming November presidential election.

The crowd drew about 15,000 to 20,000, less than 30,000 organizers were predicting, according to Religion News Service.

The all-day event drew "science guy" Bill Nye, comedian Julia Sweeney, magician Penn Jillette, Maryland State Sen. Jamie Raskin and NASA scientist Carolyn Porco. Besides speakers, it included musical acts and videos.

Also, a small group of protesters appeared at the event with some holding signs that said "God Doesn't Believe in Atheists."

The event was near the Lincoln Memorial where Martin Luther King Jr. gave his "I Have a Dream" speech 53 years ago.

"I have dream that some day children are encouraged to reach their full potential by providing them with the tools they need to learn and encouraging them to question everything," said Lawrence Krauss, a theoretical physicist and atheist activist.

The Reason Rally 2016 focused on serving as a voting bloc for the November presidential election.

"We're like 10 blocks from the White House, so let's make [President] Obama hear us. We're also calling this a voter bloc party," declared Lyz Liddell, executive director of the Reason Rally Coalition.

Many participants are supporting Bernie Sanders, who says he is "non-religious" Jew.

"He seems to be the only candidate that really cares about everybody," said Brenda Germain, from Aberdeen, North Carolina. Germain, a member of the group Military Atheists and Secular Humanists of Fort Bragg told CNN.

Speakers addressed sex education in schools, climate change, dialogue with lawmakers in Congress and transgender people's use of public restrooms.

Porco said dealing with issues is not to "pray the problems away, but to think the problems away.

Raskin, a Democratic candidate for the U.S. Congress, in his speech mentioned "our last great Republican president Abraham Lincoln who spoke of government of the people, by the people and for the people."

"He was the kind of Republican who would never make it out of the Ohio caucuses today," Raskin said.

Pew Research Center's 2014 Religious Landscape Study of 35,071 American adults found that 3.1 say they are atheists when asked about their religious identity. An additional 4.0 percent of Americans in the survey call themselves agnostics.