WASHINGTON—The Senate was poised to pass sweeping revisions to the U.S. tax code early Saturday after Republicans navigated a thicket of internal divisions over deficits and other issues to place their imprint on the economy.

The bill, which included about $1.4 trillion in tax cuts, would lower the corporate tax rate from 35% to 20%, reshape international business tax rules and temporarily lower individual rates. It also touched other Republican goals, including opening the Arctic National Wildlife Refuge to oil drilling and repealing the mandate that individuals purchase health insurance, punching a sizable hole in the 2010 Affordable Care Act. But some goals, like repealing the alternative minimum tax, fell by the wayside in last-minute wrangling.

“In the end it all came together and we’re pretty excited about what we’ve been able to accomplish for the American people,” Senate Majority Leader Mitch McConnell (R., Ky.) said in an interview Friday. “We’ve got a corporate rate at 20% that we think makes us competitive in the world again and provided substantial middle income tax relief.”

The GOP was expected to deliver 51 votes in support of the measure, with one Republican, Sen. Bob Corker of Tennessee, expected to move against the bill because of worries it will expand budget deficits. No Democrat was expected to vote for the bill.

Senators began voting on amendments late Friday night and that continued into early Saturday. They defeated, 29-71, an attempt by Sen. Marco Rubio (R., Fla.) and Mike Lee (R., Utah) to expand the child tax credit for low-income families, which would have been paid for by setting the corporate tax rate at 20.94%.