Republican leaders plan to begin debate at 9 a.m. Wednesday even after a growing number of lawmakers have come out against the Senate-passed version of the bill.

Broadly, the legislation extends President Trump’s 2017 tax cuts, making current income-tax rates permanent, and adds some new breaks. It boosts spending on defense and border security by hundreds of billions of dollars. Those increases are offset by cuts to spending on healthcare programs, nutrition assistance and clean-energy tax credits.

The legislation extends trillions of dollars in tax cuts from Trump’s first term and implements new campaign promises, while spending billions on immigration.