What if Trump tried to go ahead with his State of the Union address at the Capitol without an invitation?

Now that President Donald Trump has given in to House Speaker Nancy Pelosi, bowing to her insistence that he not deliver his State of the Union Address in the House chamber until after the government shutdown ends, people are asking: What might happen if the president were to show up at the Capitol next Tuesday evening, regardless?

Pelosi has joked that Trump would have to deliver the speech "outside,' and there's no indication Trump would attempt such a move, but could he have charged forward with an address in the House chamber without congressional authorization?

Trump periodically visits the Capitol without much notice or congressional approval to meet with lawmakers. He even dropped by lunch with Senate Republicans during this current shutdown on Jan. 9, stopping to talk to reporters outside the Senate chamber.

The president of the United States has House and Senate floor privileges, meaning he could freely mingle about either chamber and visit with lawmakers. But in order to speak, congressional rules dictate that both the House and Senate must adopt a concurrent resolution granting that permission.

House Rule IV states that "the Hall of the House shall be used only for the legislative business of the House and for caucus and conference meetings of its Members, except when the House agrees to take part in any ceremonies to be observed therein."

Hence, the need for a concurrent resolution for each presidential State of the Union address.

The responsibility to block the president from delivering an address on the House floor would likely fall to the House Sergeant at Arms, Paul Irving, whose traditional role at the State of the Union is to announce the president’s arrival to the chamber, generally with great fanfare.

But Irving is also the lower chamber's chief law enforcement officer and is responsible for maintaining decorum in the House of Representatives.

Oh, and if Trump's goal were to gain the national spotlight, Pelosi also controls the House TV cameras -- and the on-off switch -- ensuring that any stunts pulled by Trump would never see the light of day.