Different bills have passed both houses. They need to be reconciled, and a 22% corporate tax may be a deal breaker for some while a 20% rate may be a deal breaker for others.
For individual congressmen and senators to vote against the reconciliation bill now because their precious corporate rate of 20% was not achieve would be the height of hypocrisy and political suicide.
Perhaps. Perhaps not.
Trump got them to commit - and now he is negotiating again.
Trump isn't negotiating here, the House and Senate are. Trump will sign what they send him. And if that contains a 22% rate or higher or lower then his name will be on it.
I believe he is always negotiating (reconciliation is next week), but you are 100% correct - ultimately he will sign whatever they send him at this point.
He also may be open to using the higher corporate rate to offset deficit spending (although the Senate already resolved the mechanics of that by letting some tax cuts expire). I was shocked when the GOP ran into trouble Thursday night because the Senate parliamentarian stopped a gimmick to cover up the fact that the deficit was rising too much under the plan.
This parliamentarian sure does seem to have some extra-Constitutional power.