Happy New Year. Your tax bill just went way up.

When the clock hit midnight on Jan. 1, some 70 new taxes on the middle class and small businesses went into effect, thanks to Congress's failure to prevent the expiration of popular and economically vital tax breaks on time. So some 25 million middle class Americans are now slated to get hit with the alternative minimum tax (AMT) this year. Remember: This is the tax that was originally supposed to only hit the richest 100 Americans.

This...