"The fact of the matter is if we can't get a consensus nothing happens except the abuse of power by the executive," Biden said on Monday.
"I don't know, I think Motley Crue has sold out more arenas than you have and could fill more seats than you," one Twitter user wrote.
Biden and Sanders would handily beat the president in an election, according to the new poll
Buttigieg said foreign interference in U.S. elections has "destabilized" America, and suggested Trump's statements jeopardized the "most sacred thing" in America.
"The Trump Economy is setting records, and has a long way up to go," wrote the president.
The former Harvard law professor said that even though he could support Joe Biden, he couldn't pull himself to vote for Bernie Sanders.
"That cannot be who we are going forward. We've got to be bigger, we've got to be bolder," Beto O'Rourke said when asked if Joe Biden is a "return to the past."
The poll shows 53 percent of voters say they would support Biden, while 40 percent say they would vote for Trump.
"President Trump is bringing his secret one page agreement with Mexico to Iowa," Joe Biden tweeted, after President Donald Trump help up a folded piece of paper to White House reporters on Tuesday.
"It should be made clear, and I mean this from the bottom of my heart: This is not a Republican affair," Biden said of Watergate in a 1973 speech.
"I'm sorry?" Sanders said when asked if Trump told aides to deny he trailed Biden in polls. "Again, I'm not worried about polling."
"President Trump is always strongest when he has a direct foil," his 2016 campaign communications aide Jason Miller said.
On Tuesday, Biden is scheduled to speak at three different events in eastern Iowa, while Trump will make two stops in the western part of the state.
"These are baseless lies meant to stoke fear in their viewers," TJ Ducklo, Biden campaign's national press secretary, said. "It has no place in our public discourse, and anyone amplifying it bears some responsibility for giving it legitimacy it most certainly does not deserve."
Biden posted a photo of a bracelet that his first name next to Obama's, complete with a smiley face.
"If I believe health care is a right, as I do, I can no longer support an amendment that makes that right dependent on someone's ZIP code," Biden said on Thursday.
The Democratic Party 2020 candidate walked back his support of the controversial legislation, which bans the use of federal money for most pregnancy terminations.
Bernie Sanders backed abortion rights and blasted male-dominated legislatures in a 1972 article surfaced Wednesday, revealing another decades-long contrast with Joe Biden.
Biden has faced backlash from several of his 2020 Democratic rivals after his campaign confirmed he still supported the measure.
“He has nothing but yes men that tell him all the time whatever he wants to hear,” Joe Scarborough alleged.
“I was actually sticking up for Sleepy Joe Biden while on foreign soil," the president tweeted.
"To be on foreign soil, on Memorial Day, and to side repeatedly with a murderous dictator against a fellow American and former Vice President speaks for itself,” Joe Biden's communications director said.
The president criticized the former vice president over his involvement in the controversial legislation.
“Can you imagine if Barack Obama in 2011 had said ‘oh, Ayatollah Khomeini of Iran thinks Mitt Romney is low IQ and I’m totally with him,’” Al Jazeera presented Mehdi Hasan said on CNN.
Republican Rep. Adam Kinzinger (IL), an Air Foce veteran, called out President Donald Trump on Sunday for siding with North Korean leader Kim Jong Un in attacking Democratic 2020 candidate Joe Biden.
Last week, North Korea’s official Korean Central News Agency published commentary blasting Biden as a “snob lacking even the most basic qualities of a human being, much less a politician."
Former Vice President Joe Biden joins members of Congress and other 2020 presidential candidates who have vowed to codify Roe v. Wade through legislation.
The official Korean Central News Agency published a commentary Tuesday castigating Biden, who "dared to blaspheme our dignity in the election campaigns."