On a sparkling, crisp spring Sunday morning, daffodils and crocuses in bloom, President Trump attended a Lenten service at historic St. John’s Episcopal Church, whose handsome yellow stucco walls have welcomed every president since James Madison.

Perhaps the president had the 50 victims of an apparently racist massacre in New Zealand on his mind. Perhaps he was drawn to the St. Patrick’s Day-themed elements of Sunday’s service, which included Irish hymns.

Or perhaps Sunday’s dip into presidential custom and ritual served more to point up the ways Trump’s presidency defies custom.

Other U.S. presidents have decried horror abroad as an affront to values shared among liberal democratic allies, but Trump has made no major address to mourn those gunned down last week as they worshiped at mosques in New Zealand. He has not condemned the professed white-supremacist motives of the accused killer.

After the New Zealand mosque attacks, President Trump said March 15 that white nationalism is not a rising global threat, adding that it is a "terrible thing." (The Washington Post)

Instead, Trump has spent the past few days, including the hours before and after the church service, rallying his most loyal supporters around his nationalist agenda against illegal immigration, attacking a familiar list of perceived enemies and adding new ones, all while casting himself as a victim of unfair attacks.

It was a weekend of nonstop grievances from the leader of the free world.

“It’s truly incredible that shows like Saturday Night Live, not funny/no talent, can spend all of their time knocking the same person (me), over & over, without so much of a mention of ‘the other side,’ ” Trump tweeted just before 8 a.m. Sunday. “Like an advertisement without consequences. Same with Late Night Shows.”

SNL had rerun an episode Saturday that opened with a sketch lampooning Trump as a bitter and bewildered George Bailey from the movie “It’s a Wonderful Life.”

The president suggested the federal government should target the show. “Should Federal Election Commission and/or FCC look into this? There must be Collusion with the Democrats and, of course, Russia! Such one sided media coverage, most of it Fake News. Hard to believe I won and am winning. Approval Rating 52 percent, 93% with Republicans. Sorry! #MAGA.”

The weekend barrage of presidential pique came after a difficult week and ahead of what may be another for Trump. He suffered an unusual congressional defeat last week when some Republicans joined Democrats in rejecting his declaration of an emergency to get funding for his promised wall along the southern U.S.-Mexico border. That forced Trump to issue the first veto of his presidency to negate the congressional rebuke. The New Zealand shooter invoked Trump as “a symbol of renewed white identity and common purpose.” Trump described the massacre as horrible on Friday but said he does not consider white nationalism to be on the rise, despite the findings of experts, including within his own government.

“I don’t, really,” he said Friday when asked whether white nationalism is a growing threat. “I think it’s a small group of people that have very, very serious problems.”

Trump did not speak to reporters as he and first lady Melania Trump came or went from the White House on Sunday, so the only clues to his mood came in splenetic tweets that began three hours before the service and resumed shortly afterward.

Trump rarely attends church, instead frequently playing golf on Sundays at one of his eponymous private clubs. His outings have outpaced those of President Barack Obama, whose frequent trips to the golf course Trump long criticized.

In addition to “Saturday Night Live,” Trump attacked the late senator John McCain (R-Ariz.), Democrats, the so-called “Steele dossier” linking Trump to Russian interests, the “Fake News,” and even Trump-friendly Fox News, whose weekend coverage displeased him. He likened it to CNN, which he meant as an insult, and told Fox to “bring back” host Jeanine Pirro. The Trump ally’s show was bumped Saturday night after Fox denounced her on-air suggestion last week that Rep. Ilhan Omar (D-Minn.) did not support the Constitution because she is Muslim and wears a hijab.

Trump’s tweet defending Pirro was roundly criticized by his critics as being discordant in the wake of the massacre of Muslims in New Zealand by an assailant espousing white nationalism.

“Stop working soooo hard on being politically correct, which will only bring you down, and continue to fight for our Country. The losers all want what you have, don’t give it to them,” Trump urged Fox via Twitter.

His advice to the television network to “stay strong” is extraordinary for its marching-orders tone, particularly since Fox employs several hosts who are unapologetic Trump boosters. Other presidents have criticized news coverage they consider unfair but have generally refrained from appearing to dictate to a free press.

“Be strong & prosper, be weak & die!” Trump wrote.

In between references to the “Witch Hunt” and Trump nemesis McCain, Trump’s focus Saturday and Sunday on automaker General Motors and its decision to close an Ohio assembly plant suggest unease over his economic argument for reelection.

“Democrat UAW Local 1112 President David Green ought to get his act together and produce,” Trump wrote Sunday, going deep in the weeds to criticize a union leader by name. “G.M. let our Country down, but other much better car companies are coming into the U.S. in droves. I want action on Lordstown fast. Stop complaining and get the job done! 3.8% Unemployment!”

Trump campaigned on bringing back U.S. manufacturing jobs, and he uses cars as a main example.

On Saturday, Trump tweeted that GM “must” reopen the plant, “maybe in a different form or with a new owner, FAST!”

Mick Mulvaney, the acting White House chief of staff, said Sunday it was “absurd” to draw a connection between Trump’s many statements about immigration and the New Zealand shooting suspect’s reference to immigrants as “invaders within our lands.”

“The president is not a white supremacist,” Mulvaney said on “Fox News Sunday.”

Trump said during the 2016 campaign that he thinks “Islam hates us.”

The possibility that special counsel Robert S. Mueller III could on any day wrap up his investigation into the possibility of improper links between Trump and Russia hung over the White House last week, and the coming week looks no different.

Trump will host new Brazilian President Jair Bolsonaro, a populist dubbed the “Trump of the Tropics,” at the White House on Tuesday. The visit affords Trump a chance to celebrate what he considers the beneficial global influence of his “America First” agenda, and the Brazilian’s far-right views on immigration hold a mirror to Trump’s own.

Trump’s tweets about McCain ahead of the church service continued his longtime attacks on a critic who died in August from cancer but whom the president can’t seem to forgive or forget.

Trump incorrectly claimed that McCain leaked the dossier about Trump’s ties to the Russian government to try to harm Trump’s chances ahead of the 2016 election. McCain said he passed the document along to the FBI after the election.

Trump also incorrectly claimed that the Arizona Republican was “last in his class” at the U.S. Naval Academy — although the son and grandson of admirals was a famously poor student. McCain graduated fifth from the bottom of his class at Annapolis before a Navy career in which he was shot down, captured and imprisoned during the Vietnam War.

“He & the Dems, working together, failed (as usual). Even the Fake News refused this garbage!” Trump said in his third tweet in two days about McCain.

Meghan McCain, the late senator’s daughter, tweeted in response: “No one will ever love you the way they loved my father.... I wish I had been given more Saturday’s with him. Maybe spend yours with your family instead of on twitter obsessing over mine?”

John McCain had called Trump unqualified, then angered the president by siding against him in an early test of presidential will over health care.

Meghan McCain appeared to focus on the personal nature of Trump’s grievance Sunday, suggesting that the president is obsessed with her father because he resents comparison to the respected war hero.

“My father lives rent free in your head,” she said in a tweet that later appeared to have been deleted.

Lawyer George T. Conway, a rapier-tweeting Trump critic and husband of top White House counselor Kellyane Conway, surveyed the scene while Trump attended the service.

“His condition is getting worse,” he wrote.