The Senate is churning through a contentious late-night — or all-night — debate on a budget plan critical to Republican efforts to pass trillions of dollars in tax cuts and boost border security and defense spending.

Senate GOP leaders are expected to soon take a major step toward advancing President Donald Trump’s multi-trillion-dollar agenda in Congress — simultaneously setting off an intraparty war over how to pay for it.

The Senate voted 52-48 to begin debate on a multitrillion-dollar plan that would cut taxes, boost spending for immigration enforcement and the military and raise the debt limit.