While the flip still seems unlikely, this probably doesn't matter either way for 174 -- currently any bill that passes is likely to have the 174 fix in it, because it has bipartisan support. The problem has been that it's attached to other tax changes that haven't been able to get through the Senate, and Sen. Crapo is intentionally stalling until after the election, because the GOP thinks it'll have more seats and will be able to get a bill they like better.