The effort has been put off for a week, because the fast-track procedure requires unanimous consent to pass.

That should give you some idea of how concerned U.S. politicians are about a wave of Chinese auto imports flooding into and disrupting the American auto market.

Key Senate Democrats urged Trump not to open the domestic auto market before the president visited Beijing in the spring; House Democrats sent their own letter shortly later, then House Republicans did too.

Another obvious risk is what Chinese auto market access would mean to the U.S. industrial base.

In effect, it would keep the auto market from being traded away.