House Speaker Nancy Pelosi joined with other Democrat leaders Thursday in pushing for D.C. statehood ahead of a Friday vote in the House, saying making the city the country's 51st state would right a “grave injustice.”

“Tomorrow we will right this grave injustice which is an affront to our democracy,” Pelosi said at a news conference.

The Speaker noted that D.C. residents pay taxes, serve in the military and contribute to the “economic vitality” of the U.S., but do not have representation. “How could it be? Whose idea was that?” Pelosi continued.

House Majority Leader Steny Hoyer, D-Md., noted that the D.C. statehood bill, which calls for D.C. to become the 51st state, has 226 co-sponsors. He called it a “civil rights issue of our country.”

“We say that black lives matter, for too long black lives have not mattered," Hoyer said. African-Americans make up over 46 percent of the district.

Hoyer, worried Republicans might veto the legislation given the district’s liberal bent, said the constitutional framers did not think “states would be admitted on their politics.”

DC'S 'SHADOW SENATOR' SAYS 'IT'S TIME' FOR STATEHOOD, AS HOUSE PREPARES FOR VOTE 

“To consider other non-germane items in casting your vote is un-American,” the majority leader said.

D.C. Mayor Muriel Bowser echoed his cries. “Let’s fight back against the cries that we’re too liberal, we’re too black, or there are too many Democrats,” she said. “The business of America is to make sure that each person is represented fully.”

President Trump in a recent interview with the New York Post claimed that Democrats support D.C. statehood because the district is largely Democratic, meaning the party would automatically gain seats in both the House and Senate.

“They want to do that so they pick up two automatic Democrat -- you know it’s 100 percent Democrat, basically -- so why would the Republicans ever do that?” Trump said. “That’ll never happen unless we have some very, very stupid Republicans around that I don’t think you do.

“No thank you,” the president said. “That’ll never happen.”

If H.R. 51, The Washington, D.C. Statehood Act, passes the House, it would be the first time such legislation had made it through Congress. Still, it is not expected to gain any traction in the Republican-led Senate.

The last time a D.C. statehood bill was voted on was 1993. Hoyer voted against that bill, but Pelosi voted for it.

Should D.C. become a state, its mayor -- currently Bowser -- would become the new governor, and the D.C. Council would become the state legislature.

The new state would be known as Washington, Douglass Commonwealth, after Maryland abolitionist Frederick Douglass.

In Federalist 43, James Madison wrote that it is important for the nation’s capital not to be located in a state to avoid the risk that it be treated better than other states. D.C.’s “shadow senator” Paul Strauss in an interview with Fox News made clear that this would not be the case under the current plan, because the Capitol, White House, and other federal buildings would remain in its own neutral area, with only the surrounding area being part of the new state.

But the White House Office of Management and Budget (OMB) issued a statement Wednesday arguing that the tiny federal district could still be beholden to the new state.

“For example, given its small size, the Federal capital would depend entirely on the new State of Washington, D.C. for most, if not all, of the necessary modern services, which directly implicates a concern that troubled the Framers,” OMB said.

The OMB statement also argued that the current House bill is unconstitutional because of how it would take land away from the current district to form a state.

CLICK HERE TO GET THE FOX NEWS APP

“If, as H.R. 51 proposes, the District were reduced to a small jurisdiction made up of essentially only Federal buildings, the 23rd Amendment would give the tiny population of individuals living within those borders the same voting power in the Electoral College as the smallest state in the country,” the statement said.

Fox News' Ronn Blitzer contributed to this report.