After gaining national attention in his failed run against Republican Ted Cruz, the 46-year-old O'Rourke, announced his candidacy for president in a video posted to his Twitter page on March 14, calling for common sense immigration laws, gun control, climate change solutions and affordable healthcare.
"The challenges we face are the greatest in living memory. No one person can meet them on their own. Only this country can do that, and only if we build a movement that includes all of us," he wrote alongside the video.
O'Rourke is among several prominent Democrats, including many in Congress, vying for the Democratic nomination for president.
At his first campaign stop at a coffee shop in Burlington, Iowa, he called for unity between political parties.
"Let us not allow our differences to define us at this moment," he said. "History calls for us to come together, to show ourselves, our fellow Americans, the generations that follow, what we are made of and what we can do. And the only way to get that done is to get it done together."
Throughout his political career representing El Paso, Texas, a border town President Donald Trump has often evoked in his call for a wall, O'Rourke has championed efforts for legal routes to citizenship.
"We should ensure that there are lawful paths to work, to be with family and to flee persecution," he said in his campaign video.
O'Rourke countered Trump's February rally for a border wall in El Paso by hosting his own event nearby that drew thousands of supporters.
In the midst of his Senate race in September, O'Rourke spoke out against the planned expansion of a "tent city" in Tornillo, Texas for unaccompanied migrant children detained at the border and the practice of separating children from their parents there.
"This country of immigrants, this inspiration to the rest of the world, this cannot be us. This one is on all of us. It is up to all of us to make it right at this moment," he said.
O'Rourke has called for a ban on the sale of assault rifles, denouncing the idea of arming teachers and calling for universal background checks for gun purchases.
"We need universal background checks in this country. No more loopholes. Common sense, supported by most Americans, and will save lives in our communities," he said.
In his campaign video, O'Rourke called climate change the greatest challenge in the world calling for ingenuity and creativity to overcome it. He has said he liked the Green New Deal, but stopped short of fully endorsing it.
He also called for every single American to have the ability to see a doctor and "be well enough to live to their full potential." In the past O'Rourke has supported a range of healthcare options including a single-payer system and strengthening the Affordable Care Act.
Robert "Beto" O'Rourke was born on Sept. 26, 1972, in El Paso. His mother Melissa Martha O'Rourke owned a furniture store and his father, Pat O'Rourke, served as county commissioner from 1978 to 1982 and as a county judge from 1982 to 1986. His father also worked on Rev. Jesse Jackson's presidential campaign in 1988.
O'Rourke's family is of Irish descent and he was given the nickname "Beto" as a child, a common Spanish nickname for the name "Roberto" in order to distinguish him from his grandfather of the same name.
He married his wife, Amy O'Rourke, in 2005 and the couple have three children -- Ulysses, Henry and Molly.
Beto O'Rourke served on the El Paso City Council from 2005 to 2011 and was elected to the U.S. House of Representatives in 2012 after defeating Democratic incumbent Silvestre Reyes in a primary.
In 2018, O'Rourke challenged Cruz, who ran for president in 2016, in the midterm elections. O'Rourke lost by less than 3 percent, but managed to raise a record $80 million for the Senate race.
O'Rourke has pledged to run his presidential campaign in the same grass-roots manner as his Senate campaign, refusing corporate PAC donations.
More than $36.8 million of the funding for his Senate campaign came from small donors with just $83,441 or 0.11 percent coming from PACs, according to the Center for Responsive Politics.
He received $61 million through the online portal ActBlue, which provided an avenue for supporters to make recurring small-dollar gifts to candidates.
O'Rourke also received 48.1 percent of his funds, totaling $21,389,899, from women.
"We showed that it wasn't actually something that made us weaker, it made us much stronger only to rely on people," he said.
His presidential campaign raised more than $6 million in its first 24 hours almost entirely online from all 50 states.