A statehood bill was passed by the House but not taken up by the Senate, so it would need to be re-introduced in the next session. Here's the bill that the House passed:
https://www.congress.gov/bill/116th-congress/house-bill/51
D.C.'s pathway to statehood would take the same path as our most recent admissions Hawaii and Alaska ... a bill passed by Congress and signed by the President. But unlike their failed efforts to deny statehood to Hawaii and Alaska, the Republican Party will likely succeed in denying statehood to D.C.
If the Democratic Party maintains control of the House the bill will be re-introduced, then the Republican Party will prevent the bill from clearing the Senate either by preventing its introduction (if they maintain control of the Senate) or filibustering it (if they lose control of the Senate).
More if and then's ...
...
if a statehood bill does pass both House and Senate,
then it's off to the White House for the president's signature (if Biden) or veto (if Trump).
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if the bill is signed into law,
then members of the Republican Party will craft a lawsuit claiming the law is unconstitutional.
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if the Republican Party maintains control of the Supreme Court,
then the Court will find the D.C. statehood law unconstitutional.