The truth is that Congress knows that there is a sufficient basis under the law for Trump to invoke those tariffs because we are getting screwed. But they don't want the law enforced. It's so typical -- they want to virtue-signal that they're standing up for American workers by passing laws that enable retaliation for unfair trade practices, but they don't really want those powers to be used.
If they are against tariffs period, even in retaliation for us getting screwed, then they should be upfront about it and just repeal the damn law that gives the President that authority in the first place.