Two mass shootings in the US that killed 29 people has led Democratic party candidates to point the finger at US President Donald Trump. In shootings just 13 hours apart, 20 were killed in a Walmart store on Saturday morning <a href="https://www.thenational.ae/world/the-americas/el-paso-shooting-20-people-killed-at-mall-in-texas-border-town-1.894100">in the heavily Hispanic border city of El Paso</a>, followed by nine more deaths on Sunday in Dayton, Ohio. Saturday's carnage ranked as the eighth-deadliest mass shooting in modern US history, after a 1984 shooting in San Ysidro, California, that killed 21 people. On the US presidential campaign trail, several Democratic candidates denounced the rise of gun violence and repeated calls for tighter controls. At least two candidates, Mayor Pete Buttigieg of South Bend, Indiana, and El Paso native Beto O'Rourke, a former congressman, drew connections to a resurgence in white nationalism and xenophobic politics. "America is under attack from home-grown white nationalist terrorism," Mr Buttigieg said at a candidates forum in Las Vegas. Mr O'Rourke said on CNN that the president's style of politics had a role to play in the recent violence. "Let's be very clear about what is causing this and who the president is," he said. "He is an open avowed racist and is encouraging more racism in this country." Former vice president Joe Biden told the Las Vegas forum that the incident was "beyond anything that we should be tolerating". "We can beat the gun manufacturers," Mr Biden said. The El Paso gunman was identified as Patrick Crusius, 21, from Allen, which is a nearly 10-hour drive from the town. El Paso police chief Greg Allen said authorities were examining a manifesto from the suspect that showed "a potential nexus to a hate crime". Officials declined to elaborate and said the investigation was continuing. But a four-page statement posted on 8chan, an online message board often used by extremists and believed to have been written by the suspect, called the Walmart attack "a response to the Hispanic invasion of Texas". It referred to the Christchurch mosque massacres in New Zealand, claiming support for the gunman who killed 51 people at Friday prayers in March. Democratic senator Bernie Sanders also took Mr Trump to task, saying on Saturday that "we must come together as a nation to reject this dangerous and growing culture of bigotry espoused by Trump and his allies". A hallmark of Mr Trump's presidency has been his determination to curb illegal immigration. He has drawn criticism for comments disparaging Mexican immigrants and referring to migrants trying to enter through the US southern border as an invasion. Democratic senator Cory Booker, another candidate for his party's presidential nomination, also took to CNN to say<em> </em>that "Donald Trump is responsible for this". "He is responsible because he is stoking fears and hatred and bigotry." But acting White House chief of staff Mick Mulvaney told ABC's <em>This Week</em> that no politician was to blame for mass shootings. Mr Mulvaney said that the Walmart killer appeared to have been motivated by beliefs that he held before Mr Trump became president. "This was a sick person. The person in Dayton was a sick person," he said. "No politician is to blame for that. "The person who was responsible here are the people who pulled the trigger. "We need to figure out how to create less of those kinds of people as a society and not try to figure out who gets blamed going into the next election." Police and FBI investigators in Texas searched for clues on Sunday to explain what drove the young gunman. More than eight in 10 residents of El Paso, which was once part of Mexico, are of Hispanic descent. The suspect was booked on capital murder charges, jail records show. The Justice Department department is seriously considering federal hate crime charges against the gunman, which could lead to the death penalty, a source told AP.