House Speaker Nancy Pelosi sent President Trump a letter Wednesday morning suggesting he postpone his State of the Union address, or deliver it in writing, because of the government shutdown. Afterward, there was a bit of confusion. Was she actually disinviting him, or simply urging him not to come?

Neither, technically.

Though Pelosi (D-Calif.) invited Trump to give the annual address on Jan. 29, she had not pushed through the legislation necessary to make it happen. It’s not unusual for the speaker to wait until a few days before the speech to file what’s called a “concurrent resolution” that sets the day and time of the traditional speech. The measure must be passed by both chambers.

If Pelosi doesn’t file the resolution, there will be no presidential address before Congress. In her letter, Pelosi suggested that Trump could send his speech in writing to Capitol Hill. She later said he could also deliver it to the American people from the Oval Office.

Is that unconstitutional?

No.

Most of what we have come to associate with the State of the Union is tradition, not law. There is nothing in the Constitution that says the president must be allowed to give a live, in-person update on the country. Rather, there is a constitutional provision stating that the president “shall from time to time give to the Congress Information of the State of the Union."

Presidents George Washington and John Adams gave in-person addresses, but Thomas Jefferson sent a written version instead. Others followed suit. It wasn’t until 1913 that President Woodrow Wilson decided he would revive the practice of delivering important speeches in Congress.

At the time, The Washington Post wrote: “Disbelief was expressed in congressional circles when the report that the President would read his message in person to the Congress was first circulated.” But The Post assured readers that such spectacles were “not to become a habit.”

Since then, there have been 83 in-person presidential addresses, according to the House historian.

In modern times, the speech has become less a commentary on the state of the country than a massive national platform for the president to espouse his accomplishments and push his agenda. It has famously become a sort of whack-a-mole affair, where lawmakers bop up and down from their seats to give standing ovations — though typically the opposing party remains seated in silent protest. (Except, often, when veterans are mentioned.)

In 2011, Democrats and Republicans buddied up to sit together during President Barack Obama’s speech in a show of bipartisanship. But the symbolic gesture fell away in subsequent years. Moreover, a group of House Democrats did not even show up for Trump’s address last year.