The top Democrat on the House Budget Committee is wondering if Republicans can unite to pass a budget this year.

House Speaker Paul Ryan (R-Wis.), a former Budget chairman, has said that GOP leaders are poised to “hit our benchmarks” on government funding, with President Trump’s budget proposal, released Thursday, as the first step of that process.

But Rep. John Yarmuth (D-Ky.), the ranking member of the Budget panel, said long-standing divisions within the Republican Party — particularly on government spending issues — raise real questions about whether Ryan can rally his troops behind a resolution.

Yarmuth said he has not spoken with Rep. Diane Black (R-Tenn.), the Budget chairwoman, about the issue. But he sees an increasing likelihood that the Republicans will have to fall back on current authorization levels to dictate the spending debate this year — a scenario that would be an embarrassing set-back for Ryan and the Republicans, who want to prove their ability to govern effectively under their first united government in over a decade.