Nearly 1 in 5 Americans back the people who stormed the US Capitol during Wednesday’s fatal riots, a new poll found.

Nineteen percent of those surveyed late Wednesday by Ipsos said they support the fervent President Trump backers who breached the west side of the building, compared to 70 percent who said they opposed them and 11 percent who weren’t sure or didn’t know.

Seventy-four percent of those polled, meanwhile, said those who breached the building should be arrested — while 31 percent of Americans said the protests and ensuing riots were “necessary” to protect the nation.

But at the same time, more than half of Americans — 51 percent — said the riots represented an attempted coup, demonstrating the seismic political divide in the country as Trump exits the White House.

Nearly all of the 500 US adults surveyed — 87 percent — were aware of the Capitol unrest, according to the poll. Fifty-nine percent said they supported the handling of the breach by Capitol Police and other law enforcement officers, compared to 22 percent who did not.

The violent breach left five people dead, including Capitol Police Officer Brian Sicknick, who reportedly was struck in the head with a fire extinguisher during the riots and died at a hospital Thursday.

A slim majority — 51 percent — also reported that they believe Trump should be “immediately removed” from office for promoting the protests that would later descend into deadly violence as far back as mid-December.

“Big protest in D.C. on January 6th,” Trump tweeted on Dec. 19. “Be there, will be wild!”

Just 27 percent of respondents, meanwhile, said they disagreed that people need to protect America if elected leaders do not, compared to 22 percent who said they didn’t know.

The snap poll, conducted between 5:30 and 9 p.m. Wednesday, has a margin of error of plus or minus 5 percentage points.