The Senate voted on Wednesday 54-46 to end U.S. support for the Saudi-led war in Yemen, likely setting up the first veto of President Trump's presidency.

Why it matters: The bill is a rebuke of Trump's foreign policy amid broader pushback over his defense of Saudi Arabia, whose role in the conflict has been under heightened scrutiny since the murder of journalist Jamal Khashoggi. The war waged by Saudi Crown Prince Mohammed bin Salman has resulted in the world's worst humanitarian crisis, with an estimated 80% of the population in need of some sort of aid or protection.

Details: The bill, co-sponsored by Sens. Bernie Sanders (I-Vt.), Mike Lee (R-Utah) and Chris Murphy (D-Conn.), leans on the War Powers Resolution of 1973, which states that if American troops are entangled in "hostilities" overseas "without a declaration of war or specific statutory authorization, such forces shall be revoked by the President if the Congress so directs by concurrent resolution."

This is the second time the GOP-led Senate has passed the bill, though it wasn't taken up by the House in the last Congress.

The big picture: As the New York Times' Catie Edmondson notes, the passage of the Yemen bill one day before the Senate is expected to pass a resolution disapproving of Trump's border emergency "sets up something of a one-two punch for senators hoping to defy the president."