Nancy Pelosi knows how to hit President Trump where it hurts.

With the government shutdown dragging on, the speaker of the House on Wednesday sent a letter ​suggesting Trump "reschedule" his scheduled State of the Union address​, or maybe even just send it over to Capitol Hill in written form, like a book report. Was it a formal disinvitation? ​Maybe, maybe not,​ but it sure smelled like one.

Formally, Pelosi's reason for making the suggestion is that the shutdown might compromise security arrangements for the event, which nearly every senior official in all three branches of the federal government attends. "Both the U.S. Secret Service and the Department of Homeland Security have not been funded for 26 days now," she noted in the letter, "with critical departments hamstrung by furloughs."

Less formally, it seems likely that Pelosi is using the power of her office to do the one thing most likely to get under Trump's skin — deprive him of the spotlight.

The president of the United States is always at the center of attention, and this president more than most. For a few days each year, the State of the Union makes the spotlight even brighter. God knows why — the speech is usually a snoozer, a laundry list of policy goals that often come to little fruition. Despite that, it's unavoidable: Congress is there, as is most of the Supreme Court, along with a number of other luminaries. The media spend a few days anticipating the speech, which is carried live by the broadcast networks. Outside of inauguration ceremonies, the modern State of the Union is the ultimate display of presidential prestige and pageantry. Which means it's a moment made precisely for Trump's manifest love of being seen.

And Pelosi, it appears, just took it away from him. It's always fun to see the president's vanity poked, and Pelosi is ​particularly skilled​ at ​that task.​ But her denying Trump a chance to give the State of the Union address is notable for another reason: It takes the president's own practice of busting the norms of governance and good political behavior and uses it against him.

It's habitual for Congress to invite the president to give the State of the Union address, and it is a custom that has congealed into a regular feature of America's civic life. But it hasn't always been this way. While the Constitution requires the president to periodically report on the state of our Union, for more than 100 years, that report was mostly delivered in writing — until Woodrow Wilson decided to give a speech in person instead.

But this is a political norm that can indeed be broken: ​Back in 2014​, some Republicans pressured then-Speaker John Boehner to disinvite President Obama because of Obama's executive action to defer deportations for so-called "DREAMers."

Boehner blinked. Pelosi, it seems, has not. That's a good thing.

The list of norms Trump himself has broken while in office is too lengthy for a complete account in this space. He has insulted military families, attacked the judiciary, proclaimed the media the "enemy of the people," treated the Department of Justice as though it should be acting in his personal service, kept hold of his business interests from private life, and coddled dictators. And those are just some of the highlights.

The irony of Trump's norm-busting is that he still expects to be treated like a normal president. It hasn't worked out that way: He's been unwelcome at the Kennedy Center Honors, skipped the White House Correspondents Dinner, and been snubbed by championship teams in the NFL and NBA.

One important standard has survived, though: the media's longstanding belief that "if the president says it, it's news." That has allowed Trump to amplify his Twitter insults and commandeer network TV time, to little useful effect.

Now Pelosi is giving Trump a taste of his own norm-busting medicine, and you have to suspect he hates it. Depriving the president of a live television appearance may discomfit him in a way that other government shutdown narratives have not. A president accustomed to the spotlight may not have anticipated that the House speaker might simply pull the plug. Whether it leads him to end the shutdown, of course, is another question.

There is, as always, some danger in this: Norms exist for a reason — they're not hard-and-fast requirements, but they do help order the social and political landscape. It's not a coincidence that as Trump has broken informal rules left and right, the result has been most often described as "chaos." It's not wrong for Democrats to use the president's own techniques against him: Sometimes to fight a forest fire ​you have to set a counterfire​. It does mean, however, there will be more scorched earth in need of regrowing and replanting afterward.