(Adds background, O'Rourke, Trump comments)
By Tim Reid and Roberta Rampton
EL PASO, Texas, Feb 11 (Reuters) - Beto O'Rourke, the former Democratic congressman considering a White House run, and President Donald Trump traded political blows on Monday in rival rallies in El Paso, Texas, over the Republican's fight for a border wall.
O'Rourke, who narrowly lost a 2018 bid for a U.S. Senate seat, accused Trump of stoking "false fear" about immigrants and telling "lies" about his hometown El Paso, which Trump said was a dangerous place before it had a border fence.
"Here is one of the safest cities in the United States of America, safe not because of walls but in spite of walls," O'Rourke told a crowd of several thousand supporters, many waving "Beto 2020" signs and wearing "Immigrants Make America Great" baseball caps.
Two hundred yards away in El Paso County Coliseum, Trump told his supporters that O'Rourke had "little going for himself."
"We are all challenged by a young man who lost an election to (Republican Senator) Ted Cruz," said Trump, surrounded by banners reading "Finish the Wall."
Trump was in El Paso to argue for a wall he says can protect Americans from violent criminals, drugs and a "tremendous onslaught" of migrant caravans.
The rally was his first direct clash with a potential 2020 rival, albeit on separate stages.
As Trump and O'Rourke spoke, U.S. congressional negotiators in Washington said they had reached a tentative deal on border security funding to avert another partial government shutdown due to start on Saturday.
An aide said it did not include the $5.7 billion Trump has demanded for his wall, however.
"BUILD THE WALL"
O'Rourke relished the prime-time national platform, sometimes breaking into Spanish as he decried the Trump administration's separation of immigrant children from their parents at the border.
He said Dreamers - undocumented people brought to the United States by their parents when they were children - should be given citizenship, and their parents a pathway to citizenship.
"With a president who describes Mexican immigrants as rapists and criminals, we have a chance to tell him and the country that immigrants commit crime at a lower rate that Americans who are born in this country," he said to shouts of "Beto, Beto."
Trump traveled to the Democratic bastion of El Paso county in the heavily-Republican Texas to hammer on immigration issues that delighted his followers.
"I will never sign a bill that forces the mass release of violent criminals into our country," Trump said, referring to a Democratic proposal in the Washington talks to lower the cap on detentions of criminal aliens by Immigration and Customs Enforcement (ICE).
A congressional aide said under Monday's tentative agreement, the cap would likely stay around the same in previous years.
Trump said he had heard about progress in the talks before he took the stage, but did not mention details.
"Just so you know - we're building the wall anyway," he said, to huge cheers.
For much of his speech, Trump recounted accomplishments from his first term. He was also interrupted several times by protesters in the crowd who were escorted out by security.
"BUILD THE WALL!" the crowd chanted as they were led out.
Although O'Rourke's full-throated denunciation of the president sounded like a campaign speech, the two-time congressman declined to discuss a potential run on Monday when asked by reporters on a conference call.
O'Rourke told Oprah Winfrey last week he would make a final decision about running for president by the end of the month. (Reporting by Tim Reid in El Paso, additional reporting by Steve Holland and Tim Ahmann in Washington; Writing by Andrew Hay; Editing by Colleen Jenkins, Bill Tarrant and Sonya Hepinstall)
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