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.

The vote is one big step in a long process. And the debate revealed intra-party tension over key issues like Medicaid, tax-cut strategy and the debt.

An amended version of the House-passed Trump budget was voted on at the end of a marathon vote series in the Senate.