What would the public reaction be today if Congress passed a major legislative proposal where the public had no forewarning?

Would it be difficult for Congress to persuade the public such legislation was in the public's best interest?

What would be the reaction of the media and political leaders at the state level to decisions that violated the Constitution?

I'm trying to find any legislation that congress might have passed without public knowledge and the only thing I can find is the recent change to the fair trade act without public knowledge - any ideas?