Allan Baxter via Getty Images A petition for the District of Columbia to become the 51st state will be sent to Congress after Washingtonians voted for statehood Tuesday, D.C.'s mayor said.

Washingtonians took another step toward statehood, but they’re likely to be tripped up again.

An overwhelming 79 percent of District of Columbia residents voted Tuesday to become the 51st state, with the mayor vowing to send the petition to Congress for approval by Inauguration Day on Jan. 20.

“Their votes confirmed what we all knew is that Washingtonians are tired of being treated like second-class citizens,” Mayor Muriel Bowser said at a Wednesday afternoon news conference.

”There will be many twists and turns ahead ― just like there have been good days and not so good days in DC’s history,” she said in an accompanying statement, “but we take this monumental step forward together, we can be sure that DC’s best days are ahead of us.”

One twist is that, should the District become a state, two more seats would be added to the Senate. According to The Washington Post, this has drawn resistance from Republicans, as those seats would likely be held by Democrats, who have an overwhelming majority in the District.

That means Tuesday’s big win for the Republicans, in both the presidency and the U.S. House, will likely make the petition’s final approval by Congress a dead issue.

Susan Walsh/AP Washingtonians voted nearly 80% in favor of becoming a state.

As part of the draft constitution voted on Tuesday, residents would elect a governor rather than a mayor, as well as a 21-seat state legislature instead of a city council. State lines would have to be drawn, with the White House, the Capitol and the National Mall remaining in a federal district, CBS Washington reported. A final state constitution would be reviewed by residents before approval, Bowser stated.

The draft constitution listed the new state’s name as New Columbia, but the name isn’t final, DCist reported in October.

D.C. residents have long petitioned for statehood. Since 2000, the district’s standard license plates have included the phrase: “Taxation without representation.”

Kevin Lamarque / Reuters The district's license plates read, "Taxation without representation." This one was on a motorcade vehicle of President Barack Obama in 2013. He had the statement reinstated after his predecessor, George W. Bush, had it removed.

This phrase refers to D.C. residents’ lack of a voting representative in the U.S. House, as well as the city not having representation in the U.S. Senate. Congress maintains authority over the city, including the power of final approval over legislation from the city council.

Then-President Bill Clinton placed the statement license plates on his presidential motorcade during his last few weeks in office. In 2001, his successor, George W. Bush, was sworn in and had the plates removed soon after. They were not reattached again until 2013, during President Barack Obama’s second term in office, The Washington Post reported.

“President Obama has lived in the District now for four years, and has seen first-hand how patently unfair it is for working families in D.C. to work hard, raise children and pay taxes, without having a vote in Congress,” the White House said in a statement at the time.

President-elect Donald Trump was asked during his campaign last year for his response to D.C.’s bid for statehood on NBC’s “Meet the Press.” He said that he would do “whatever’s best” for the people of D.C. and that “something would be done that everybody would be happy,” NPR reported.

This article has been updated to include more information about D.C.’s plates.