On Monday, the House Committee on Oversight and Reform held a hearing on H.R. 51, a bill to grant statehood to the District of Columbia. The measure has nearly unanimous Democratic co-sponsorship in the House and Senate. Given Democrats’ narrow chamber majorities, it could pass this session, provided Senate Democratic leadership convinces four holdout members to support the bill and can circumvent a Republican filibuster.

This combination of clear progress but high hurdles fits with the history of the centuries-long struggle for District home rule. As D.C. Del. Eleanor Holmes Norton testified, “My own family has lived through almost 200 years of change in D.C. since my great-grandfather Richard Holmes, as a slave, walked away from a plantation in Virginia and made his way to D.C. Today, it is my great honor to serve in the city where my family has lived without equal representation for almost two centuries.”

D.C. residents have gained rights in fits and starts, often running into both constitutional and congressional hurdles. In recent decades, members of Congress have raised new impediments, driven by partisanship tinged with racism.

H.R. 51 addresses a long-standing oversight in the U.S. Constitution. The Constitution’s Enclave Clause empowers Congress to “exercise exclusive legislation” over the District of Columbia. While many think the Constitution explicitly excluded D.C. from congressional representation, D.C. residents initially elected special representatives to Maryland and Virginia’s congressional delegations. But in 1801, Federalists in Congress, reeling from significant losses in the 1800 election, passed the District of Columbia Organic Act, seizing control over the District, stacking D.C. courts with party allies and withdrawing District residents’ congressional representation.

The 1801 Act imposed an appointed mayor and council on Washington, and this governing structure remained in place until Reconstruction. After the Civil War, Republicans aimed to cement their power by aggressively converting Republican-leaning territories into states on party-line votes — it admitted the Nevada Territory in 1864 with only 21,000 residents. In 1871, Congress organized the Republican-leaning District into a territory with a governor, an elected bicameral legislature and a congressional delegate, pushing D.C. a step closer to statehood.

But District infrastructure projects ran over budget, souring members of Congress, who three years later demoted Washington to a federal district managed by an appointed three-member commission. Republican members of Congress increasingly neglected District statehood concerns, instead focusing on admitting Republican-leaning Western states to pad their slim Senate majority. Between 1889 and 1890, Republicans added six states — North Dakota, South Dakota, Washington, Montana, Idaho and Wyoming — and 12 Republican Senate seats.

Meanwhile, the commission and the House District of Columbia Committee resisted reforming D.C’s governing structure or granting self-determination for Washingtonians for the next century. Committee Chair John McMillan (D-S.C.), a fervent segregationist, alone killed a half-dozen D.C. home rule bills between 1948 and 1966.

Tides turned with the civil rights movement. In 1961, the 23rd Amendment passed with bipartisan support, granting District residents the right to vote for presidential candidates. As White flight and the repeal of Jim Crow disenfranchisement increased Black voting power in the District, Washington’s electorate skewed Democratic. This encouraged congressional Democrats to address D.C. residents’ statehood and home rule petitions.

Under President Lyndon B. Johnson, therefore, Congress in 1967 repealed the commissioner system and instituted an appointed mayor and council. In 1970, Washingtonians won the right to elect a nonvoting delegate to the House, and in 1973, to elect their mayor and council. Walter Fauntroy, the first elected delegate, campaigned in South Carolina in 1972 to help secure McMillan’s ouster from Congress and the District Committee. And in 1978, congressional Democrats and Republicans united to pass the D.C. Voting Rights Amendment to grant D.C. full congressional representation, sending the measure to the states for ratification.

In the 1980s, however, the momentum for D.C. home rule and representation stalled. Republicans increasingly opposed statehood for the left-leaning District, and conservative Southern Democrats still refused to enfranchise the District’s majority-Black electorate. District residents in 1980 approved a call for a specially-elected state constitutional convention, which in 1982 drafted a new, politically progressive state Constitution, but Congress ignored the document. And only 16 of the necessary 38 states voted to ratify the D.C. Voting Rights Amendment by the 1985 deadline. In 1990, Sen. Ted Kennedy concluded that for Republicans and Southern Democrats, “The District of Columbia and its residents are too urban, too liberal, too Democratic, and too Black.”

Statehood bills in the 1990s and 2000s fared little better. As the District fell into debt, a 1993 statehood bill failed in the House, with 105 Democrats voting in opposition after their leadership failed to adequately push for the bill amid concerns about D.C’s financial management. As both parties polarized, Democrats in Congress increasingly supported the push for District statehood, home rule and representation. But congressional Republicans nearly uniformly opposed the movement, defeating a 2007 bill for full D.C. House representation and reversing liberal D.C. Council measures, often to demonstrate a conservative track record before their Republican constituents.

Today’s pending statehood bill attempts a new approach, converting much of the current District into a new state, “Washington, Douglass Commonwealth,” while maintaining congressional control over a reduced federal district encompassing mainly the Mall, to comport with the Enclave Clause. For this reason, granting statehood to much of the current District would not require an amendment to the Enclave Clause, as some Republicans allege. The bill also calls for repeal of the 23rd Amendment, which would apply only to the reduced federal district.

Despite these constitutional workarounds, H.R. 51 has drawn Republican objections. Last June, Sen. Tom Cotton (R-Ark.), recalling a 1783 case in which the Pennsylvania militia refused to protect the Continental Congress from a Philadelphia mob, argued against entrusting defense of the Capitol building to a new state governor or to the District’s current Mayor Muriel E. Bowser (D).

But this argument lost force on Jan. 6 when violent supporters of President Donald Trump stormed the Capitol, and the Department of Defense rebuffed Bowser’s request for National Guard support. Instead the mayor sent the District’s own Metropolitan Police officers, many of them District residents, who were injured defending the Capitol in which they have no vote.

Republicans’ larger objections are political; they worry that D.C. statehood would likely mean two new Democratic senators and full voting rights for the District’s nonvoting House representative. They have even taken to making this argument explicitly. But while the practice has faded from popular memory, partisan motives and votes have been the norm for admission of new states since the late 19th century.

Even if Democrats can muster the votes to overcome Republican opposition, another hurdle remains: the Supreme Court. In 1875, the court upheld Congress’s authority to redraw or cede District territory, but the current conservative court may not be so charitable to H.R. 51. While nearly all of the hundreds of proposed state constitutions have been drafted by elected conventions, H.R. 51 calls for forming a state government under a 2016 constitution that was not drafted by a specially-elected convention. Citing this, the court could plausibly reject the proposed constitution for failing the U.S. Constitution’s requirement that states impose a “republican form of government.”

These hurdles to H.R. 51 are not new. The history of the D.C. statehood movement has been one of incremental gains against entrenched congressional opponents and constitutional constraints. But the current bill, poised for passage in the House and perhaps in the Senate, is as close as the District has come to statehood in nearly two and a half centuries.