As the sun rose in Washington, senators passed theirtwentieth hour of debateon PresidentDonald Trump'stax, spending and policy bill − with the finish line still unclear. Thelegislation includes provisionson Medicaid reform, increased border security funding and limits to taxes on tips and overtime wages. The outcome in Congress is expected to be either a defining legislative win for Trump or a major setback early in his second term. Despite working through the weekend, senators continued to hash out disputes on and off the floor of the Senate throughout the night June 30 and into the morning of July 1. Majority Leader John Thune, R-South Dakota, hastold reportersin the Capitol Republicans are "close" to nailing down a deal. Thune is working with a tight 53 to 47 GOP majority in the upper chamber. Republican Sens. Rand Paul of Kentucky and Thom Tillis of North Carolinavoted against debatingthe bill in the first place and are anticipated to likewise reject its final passage. With no Democrats expected to offer their support, Thune can only afford to lose one more Republican member's vote − and in that case of a 50-50 split, he would need Vice PresidentJD Vanceto enter and break the tie. Even then, Congress isn't through yet. If and when the Senate passes Trump's mega bill, it must then be reconciled in the House, where an original version passed by the smallest of margins in May. Votes in the lower chamber are tentatively planned for July 2, pending the outcome in the Senate. This article originally appeared on USA TODAY:Senate near finish line after hours of debate on Trump's tax bill