Rep. Jared Golden (D-Maine) defied House Democratic leadership on Tuesday when he voted for the GOP’s bill to avert a government shutdown — the only one in the caucus to support the stopgap.

Republicans will face a critical test of their unity when a spending bill that would avoid a partial government shutdown and keep federal agencies funded through September comes up for a vote.

Hard-line conservatives have largely fallen in line behind the House speaker's legislation to fund the government.