President Donald Trump declared the speech "Sooo Boring!'"
Trump, who was traveling to El Paso aboard Air Force One after visiting shooting victims in Dayton, was apparently watching Biden's speech.
Former Vice President Joe Biden tore into President Trump on Wednesday, accusing the commander in chief of promoting white supremacy.
Mr. Trump condemned "racism, bigotry and white supremacy" for the length of a White Residence deal with Monday.
In the first, on Saturday, a gunman killed 22 people in El Paso, a Texas city on the border with Mexico. "He is, in large part, to blame for what has taken place".
Biden invoked the rhetoric of previous presidents of both parties, including Republican George W. Bush and Democrat Bill Clinton, who he said "opposed hate".
Booker said white supremacy "allows political leaders to promise to "build the wall" - while not building hospitals, schools, or infrastructure".
Yellow weather warning issued as high winds and rain expected
There is a small chance that homes and businesses could be flooded, causing damage to some buildings. Delays and cancellations to train and bus services can also be expected in flood-hit areas.
Former Texas Rep. Robert "Beto" O'Rourke, who represented El Paso, said that there should be "universal background checks" and "a stop to all sales of weapons of war" at a Las Vegas forum on the same day of the shooting, reported the Associated Press.
The weekend's back-to-back mass shootings intensified criticism of what many say is incendiary rhetoric by Trump.
"No I don't think my rhetoric has at all, I think my rhetoric - it brings people together".
Biden will be on the Iowa State Fair soapbox at 1:30 p.m. Thursday and at the North Iowa Democrats Wing Ding in Clear Lake on Friday evening.
Biden told the crowd of almost 300 people inside the Barn on the Hill north of Burlington that he planned to talk about agriculture, unions, and rural issues during his latest swing through Iowa.
Biden also offered an indictment of Trump's leadership in a time of crisis and argued that the president's failure to "fight for what is best of the American character" makes it even more critical for the president to be defeated in 2020.
Earlier this year, Biden kicked off his third campaign for the presidency by arguing the race was about restoring the "soul of the nation" - a theme he repeated and amplified Wednesday in southeast Iowa.
The president dismissed Mr. Biden's full-throated attack.