Republican presidential nominee Donald Trump vowed Saturday in Houston, Texas, to rid the U.S. of illegal immigrants who have killed people.

“This has to end. It will end when I become president. I promise you,” Trump said during an event that was broadcast live but closed to reporters.

“Not one more American life should be given up in the name of open borders,” Trump said as he cited an example of an illegal immigrant in the Austin, Texas, area who he said was recently arrested for a dozen sexual assaults after having been deported five times within three years.

Trump said his Democratic rival, Hillary Clinton, failed to enforce immigration laws when she was secretary of state by failing to suspend the issuance of visas to countries that don’t take back their citizens.

Trump remarks came at the first conference hosted by the Remembrance Project, a group that advocates for families whose relatives were killed by illegal aliens. He helped put the group in the spotlight at the Republican National Convention in July, when he gave family members of victims an opportunity to discuss their experiences. Trump has since met many times with the group, and members often appear at his campaign rallies.

But the nonprofit organization has critics who contend it uses families of victims to promote a hateful political agenda.

Republican presidential candidate Donald Trump kis Republican presidential candidate Donald Trump kisses mothers from the Remembrance Project, who have lost sons to violence by illegal immigrants, as he speaks at a campaign rally in Austin, Texas, Aug. 23, 2016. Republican presidential candidate Donald Trump kisses mothers from the Remembrance Project, who have lost sons to violence by illegal immigrants, as he speaks at a campaign rally in Austin, Texas, Aug. 23, 2016.

'Helping' nativist movement

The Southern Poverty Law Center, which monitors hate groups, said the Rembrance Project is “helping to advance the agenda of the organized nativist movement in the United States, which tries to demonize immigrants in general, whether documented or not.”

The Center for New Community said the Remembrance Project has become an effective messenger for the anti-immigrant movement. “Rembrance Project co-founder Maria Espinoza has been more than willing to align with these extremist groups to raise the profile of her own efforts,” the hate group tracker said on its website.

There is much at stake in this election for people living in the U.S. illegally, as Trump initially promised to deport the estimated 11 million illegal immigrants and build a wall along the Mexican border. He has since softened his stance on deportations by backing off his proposal to deport people who have not committed crimes beyond their immigration offenses, but he is sticking to his promise to build a wall.

Trump enjoys a comfortable lead in Texas, according to recent polls. A poll of likely voters released Thursday by the Texas Lyceum has Trump leading Clinton 39 percent to 32 percent.

Clinton was scheduled to join President Barack Obama in Washington on Saturday at the annual Congressional Black Caucus dinner. Obama will deliver the keynote address, and Clinton will receive the inaugural Trailblazer Award for becoming the first female presidential nominee of a major political party in the U.S., and for what the CBC describes as her “remarkable contributions to the nation.”

Vermont Sen. Bernie Sanders, campaigning on Democr Vermont Sen. Bernie Sanders, campaigning on Democrat Hillary Clinton's behalf, speaks to an audience at the University of Akron in Akron, Ohio, Sept. 17, 2016. Vermont Sen. Bernie Sanders, campaigning on Democrat Hillary Clinton's behalf, speaks to an audience at the University of Akron in Akron, Ohio, Sept. 17, 2016.

Sanders, Warren campaign

Senators Bernie Sanders of Vermont and Elizabeth Warren of Massachusetts were crisscrossing the battleground state of Ohio on Saturday on Clinton’s behalf, echoing the nominee's plans to help millennials (born between the early 1980s and early 2000s) by making debt-free college available to all Americans.

Speaking at the University of Akron, Sanders said by 2021, “any family in America which has an income $125,000 or less — all of those families, 83 percent of American families — should be able to attend in-state public colleges and universities tuition-free."

Sanders also conveyed Clinton’s “very significant” plans to lower student debt by refinancing it at substantially lower interest rates and by not requiring citizens to pay back more than 10 percent of their income. “Clinton doesn’t want you to be paying off a debt for the rest of your life. You’ve got other things to do with your income,” he said.

The presence of Sanders and Warren in Ohio is part of the Clinton campaign’s effort to regain her once-sizable lead over Trump by winning over disillusioned voters who are leaning toward Libertarian Party candidate Gary Johnson or Green Party nominee Jill Stein.

These voters, many of whom are millennials, live in states that have fallen on hard economic times, primarily because of a dramatic decline in the manufacturing sector. Clinton hoped to get a boost among these voters as Sanders and Warren, two politicians young liberal voters are loyal to, planned to attend five campaign events in Ohio on her behalf. Clinton and Trump are tied in Ohio, according to the polls.

Remarks on Clinton bodyguards

The Trump campaign, meanwhile, was receiving backlash from remarks he made Friday evening in Miami, where he told an audience that Clinton's bodyguards should stop carrying guns because Clinton wants to overturn the Second Amendment, which guarantees a citizen's right to bear arms.

"I think that her bodyguards should drop all weapons," Trump said. "They should disarm, right? Take their guns away. She doesn't want guns ... and let's see what happens to her. Take their guns away. OK, it would be very dangerous."

Clinton has never said she wants to overturn the Second Amendment. She has called for tighter access to guns, including universal background checks.

Clinton campaign manager Robby Mook said in a statement that Trump's remarks about Clinton's bodyguards fell into Trump's pattern of inciting people to violence.

"Whether this is done to provoke protesters at a rally or casually or even as a joke, it is an unacceptable quality in anyone seeking the job of commander in chief," Mook said.

The U.S. Secret Service declined to comment. Both candidates' bodyguards are armed with guns.