READ MORE “Senator Corker has been pretty clear he doesn’t want any deficit spending,” said Senator John Cornyn of Texas, the No. 2 Senate Republican. The last-minute attempt to find revenue slowed, at least temporarily, what had appeared to be a cascade of momentum for the bill. Republicans picked up a key swing vote, Senator John McCain of Arizona, earlier in the day, and had appeared to be on track to pass the bill along party lines. Now, they are under pressure to cut the cost of their bill by as much as one-third, a situation that could require Republicans to insert future tax increases into what was posited as a giant tax cut. That could complicate the final approval of the tax rewrite, particularly with House Republicans, who will be loath to approve a bill that would effectively raise taxes on companies and individuals after a period of lower taxes. Several senators remain on the fence over the bill, and Republicans can lose no more than two of their members to...