WASHINGTON — The House took the first major legislative step Thursday toward enacting a promised overhaul of the tax code, approving a budget blueprint that would allow a future tax bill to pass Congress without any Democratic votes.

The House voted 219 to 206 to pass the budget resolution, with 18 Republicans voting against it.

The belated approval of a spending and revenue blueprint for the fiscal year that began on Sunday offered a momentary display of Republican cohesion as the party moves ahead in its attempt to overhaul the tax code for the first time since Ronald Reagan was president.

The document itself ostensibly charts a path toward a balanced budget over the next 10 years, giving Republicans something to offer their core conservative voters while providing Democrats with new lines of attack in the 2018 midterm elections.

But few people believe the broad spending road map will lead anywhere. What is important is parliamentary language that would shield a tax bill from a filibuster in the Senate. A week after Republicans conceded defeat in their attempt to dismantle the Affordable Care Act, that constituted a step forward in their new legislative quest.