From the Wall Street Journal editorial board:
One reason the economy struggled under Barack Obama is because he stretched the law to serve his ideology. Businesses never knew when a new regulation might hit next, and on what legal basis. Mr. Trump is making the same mistake on trade, substituting presidential whim for clear and fixed rules.
If Mr. Trump invents a national-security threat to justify car tariffs, business should fight back in court and Congress should strip his Section 232 power.