Senate Republicans are straining to meet a July 4 deadline to pass President Donald Trump‘s “big, beautiful bill” as a flurry of last-minute negotiations and legislative changes threaten to delay a final vote.

U.S. President Donald Trump and his allies in the Senate face a political free-for-all over passage of his sweeping tax-cut and spending legislation, which Republican congressional leaders hope to enact in coming days despite growing resistance from different party factions.

The Byrd Rule, adopted in 1985, is a procedural constraint named after the late Senator Robert C. Byrd of West Virginia to prohibit “extraneous” provisions from being tacked onto reconciliation bills, which are fast-tracked budget packages that allow legislation to pass with a simple majority, bypassing the 60-vote filibuster threshold.