President Donald Trump flew to Texas on Thursday to push his controversial border wall project, pulling out of a major international forum later this month with no end in sight to a row that has partially shut the US government.Trump used the backdrop of McAllen, Texas, to pursue his message that only more barriers on the frontier with Mexico can protect the United States from what he calls a torrent of violent crime committed by illegal immigrants.And in a tweet, he announced he will not attend the annual World Economic Forum in Davos, Switzerland, which runs from January 21-25. He had been expected to make a brief appearance at the get-together but said that opposition Democratic "intransigence" required him to stay home.Before leaving for Texas, Trump hammered congressional Democrats for refusing to approve $5.7bn in construction funds for the wall."If you don't have a steel barrier or a wall of some kind - strong, powerful - you are going to have human trafficking, you are going to have drugs pouring across the border, you're going to have... the gangs coming in," he said outside the White House.Because of the Democrats intransigence on Border Security and the great importance of Safety for our Nation, I am respectfully cancelling my very important trip to Davos, Switzerland for the World Economic Forum. My warmest regards and apologies to the @WEF!— Donald J. Trump (@realDonaldTrump) January 10, 2019 But Democrats say the wall would not solve real US immigration problems and is being promoted as a gimmick to satisfy the president's right-wing base.Trump has tried to pressure Congress by refusing to sign off on a host of unrelated, normally uncontroversial government spending, resulting in a partial government shutdown.Hundreds of thousands of federal employees, including air traffic controllers and members of the Coast Guard, have been without pay for three weeks as a result.Emergency threatThe frustrated president repeated his threat that if the Democrats don't back down, he will declare a national emergency to give himself authority to go around Congress."If we don't make a deal, I think it would be very surprising to me" not to declare a national emergency, he said."I'm not prepared not to do that yet, but if I have to, I will. I have no doubt about it."Analysts say the declaration would likely be challenged in court as a case of presidential overreach, in which case the wall still would face being blocked.However, it would still give Trump political cover with his base by showing he'd done what he could. At that point, Trump could end the partial government shutdown.Temper tantrum? Trump, who revels in telling stories about his negotiating skills as a New York real estate magnate, has not managed to get the Democrats to budge on his demand for the $5.7bn.On Wednesday, he invited Democratic leaders to the White House and began by asking if they would approve the wall in exchange for him ending the government shutdown. When the Democrats said no, he walked out."A total waste of time," Trump tweeted. "I said bye-bye, nothing else works!"Just left a meeting with Chuck and Nancy, a total waste of time. I asked what is going to happen in 30 days if I quickly open things up, are you going to approve Border Security which includes a Wall or Steel Barrier? Nancy said, NO. I said bye-bye, nothing else works!— Donald J. Trump (@realDonaldTrump) January 9, 2019 Chuck Schumer, the top Democrat in the Senate, told journalists Trump "sort of slammed the table," then "got up and walked out"."Again, we saw a temper tantrum because he couldn't get his way," Schumer said.Trump disputed that Thursday, saying "I didn't pound the table. That is a lie.""I don't have temper tantrums," he said. "All of that narrative is a lie."Illegal immigrants danger disputed In Texas, aid workers say people crossing the border do not present the menace that Trump claims."The truth is that a great number of percentage of people entering our country, asking to come in to the country, are not criminals: They are families, children, mothers, who really are asking for protection," said Sister Norma Pimentel, head of the Catholic Humanitarian Respite Center in McAllen, Texas."They're not coming here to hurt us but rather for us to help them."A 23-year-old Honduran who gave his name only as Kevin said he came with his toddler daughter in search of a better life."We left because of the crime, because there is a lot of unemployment. The education system is bad and all of us, we parents, want a better future for our children," he told AFP.