The right-wing pundit and author suggested she could back democratic socialist Bernie Sanders because he is strongly opposed to open borders.
The conservative pundit continued her criticism of the Trump White House.
"Stunning numbers of people trying to flood into our country, and Democrats are doing nothing about it," a Trump 2020 aide tweeted. "Neither is the president," Coulter responded.
"HEY! Who bet me that @realDonaldTrump was actually going to 'close the border'?" Coulter tweeted.
"On the upside, Ivanka got three new trademarks approved in China!" Coulter tweeted after news broke about a Chinese woman arrested for sneaking into Mar-a-Lago with two Chinese passports and a thumb drive with malware.
"Do any former Michelle Obama aides know the perps' families?" Coulter tweeted.
"You want to go after Trump?" Coulter tweeted. "Point out he hasn't kept any of his promises."
"We're so lucky there are no American kids who need wellness checks!" Coulter tweeted.
"New Zealand is a sickening tragedy," Coulter tweeted. "When will this insane terrorism end."
"URGENT SAFETY ALERT: Anyone in the vicinity of the U.S. Capitol take cover," Coulter tweeted.
"Charles Kushner paid Harvard a mere $2.5 million to get Jared into Harvard," Coulter tweeted.
"His personality is almost the opposite of 'authoritarian,'" Coulter said of Trump.
"If so, pumps or stilettos?" Coulter tweeted.
"Now, who's the 'Stupid Party'?" Coulter tweeted.
Coulter is still not happy about the unbuilt border wall.
"How do we know Trump's telling the truth about all that new border wall he's already built?" Coulter tweeted sarcastically.
"I don't think Ann Coulter has any influence over this White House, or influence over much of anything, to be honest," Sanders said. "I don't think she did before the president became the president. I don't think she does now. I just don't see her as being an influential voice in this country, and certainly not one in this building."
"Sean Hannity has been a terrific, terrific supporter of what I do," Trump said in a news conference following his announcement of a national emergency.
"The goal is to get Trump's stupidest voters to say 'HE'S FIGHTING!'" Coulter tweeted. "No he's not."
"There's no coming back from this. No "emergency" or presidential powers will allow him to build the wall, ever, after he signs this bill. Trump has just agreed to fully open borders," Coulter tweeted on Thursday afternoon.
Analysts and critics said that it was criticism from Ann Coulter and other conservative commentators that caused Trump to reverse course on signing a bipartisan spending bill last December that would have kept the government open.
"Trump talks a good game on the border wall, but it's increasingly clear he's afraid to fight for it," Coulter tweeted.
"45 minutes in, we got 30 seconds on the wall. He better be breaking ground tomorrow," conservative media commentator Ann Coulter tweeted during the State of the Union address.
"Churchill slept late, worked late, took a nap every afternoon," Gingrich tweeted in defense of Trump.
Coulter also called Trump "lazy and incompetent."
"Just as collusion is not a crime, kissing the emperor's ass violates no federal law," Coulter tweeted.