US: Biden says Trump encouraging white supremacy

President Donald Trump is encouraging the growth of white supremacy in the U.S., former Vice President Joe Biden charged Wednesday.

Biden, the leading Democratic candidate early on in the race for the party's nomination, launched a scathing salvo against the president, citing repeated instances in which Trump has used divisive nativist rhetoric to refer to minorities and immigrants.

"How far is it from Trump saying this is an invasion to the shooter in El Paso declaring 'this attack is a response to the Hispanic invasion of Texas?'" Biden asked rhetorically at a campaign rally in Iowa. "It's both clear language and in code. This president has fanned the flames of white supremacy in this nation."

Biden said the U.S. has a problem with the "rising tide" of white supremacy in the U.S., in part because of Trump -- "a president who encourages and emboldens it.”

The president responded to Biden's speech on Twitter, calling it "Sooo Boring!"

Trump is currently making his way through El Paso, Texas where a gunman opened fire on Saturday in a Walmart in the border town, killing 22 people.

The suspect, 21-year-old Patrick Crusius, was taken into custody after 20 people were killed and 26 others were injured during the attack. Two of the injured victims died at a hospital Monday.

Just minutes before the tragedy, a racist screed was posted to 8chan, a website popular with extremists, titled “The Inconvenient Truth,” which railed against an alleged "Hispanic invasion of Texas” and assailed "race mixing" while pledging an imminent attack.

“I am simply defending my country from cultural and ethnic replacement brought on by an invasion,” it said. "This is just the beginning of the fight for America and Europe. I am honored to head the fight to reclaim my country from destruction."

Investigators are attributing the writing to Crusius, a resident of Dallas, Texas.