President Donald Trump’s approval of a $1.3 trillion spending bill that widens the federal deficit and omits some of his loudest demands shows again how Congress lords it over him.

Trump haters are so invested in seeing him as a menace and his fans are so unwilling to recognize his weaknesses that both sides may fail to notice when he forfeits his authority.

Before signing the bill on Friday, Trump put on a distracting little show. First, White House officials assured lawmakers he would not veto the bill. Then he threatened to veto it. Within hours, he backed off the threat.

“I will never sign another bill like this again,” the president said once he got everyone’s attention, slamming the hasty passage of the 2,200-page plan as a “ridiculous situation.”

For weeks he stated several demands for the bill, including a lot more than the $1.6 billion provided for his southern border wall and action on the “Dreamer” program. Neither made the cut.

Trump rationalized his cave in as a way to ensure a big military spending increase — as if the House and Senate Republican majority would not have kept that in any amended bill.

Never mind that the president had mused in the past about the possible benefits of a government shutdown if Congress couldn’t meet a previous budget deadline.

Trump has carried out the same gripe-but-sign scenario before.

Last August Trump signed legislation imposing new sanctions on Russia and limiting his own authority to lift them. The bipartisan measure cleared both houses with veto-proof majorities.

Even as he gave it his signature, Trump complained the hawkish bill had “clearly unconstitutional provisions” — which could be interpreted as his violating his own oath to uphold the Constitution.

Nearly seven months later, Trump imposed stringent sanctions on Russia, including those on individuals indicted by special counsel Robert Mueller.

Discussing the budget bill on Sunday, Treasury Secretary Steven Mnuchin said in a broadcast interview that Congress could have given Trump “line-item veto” power — but was corrected by a Fox News host, who said that is unconstitutional.

According to the U.S. Senate website, Trump has yet to use his veto power. There have been 2,574 presidential vetoes since the founding of the republic.

Campaign-bound Democrats seeking a rhetorical edge often accuse the House and Senate GOP majorities of “rolling over” for Trump. To the contrary, the executive branch these days often seems to acquiesce to the legislature, regardless of all the noise.