From The Economists daily briefing.
"The 21st Century Road to Housing Act, which aims to boost American homebuilding, became law on Saturday. Mr Trump refused to either veto or sign the legislation, which the House of Representatives sent to the White House on June 29th; it automatically became law after ten working days. The president had made his approval contingent on Congressional support for a separate act that would require proof of citizenship to register to vote. It is the first time in nearly a decade that legislation has passed without a presidential signature."
So...F.U. Mr. President. Maybe Congress is finally coming around and you're not gonna like it. Public opinion is trending against you and Congress may start paying more attention to "We The People".