>>>WASHINGTON -- The United States Constitution mandates that the president address Congress on the current State of the Union.  What began as a handwritten note to congressmen has evolved into a show of televised political theatre, broadcast globally, in which a sitting president is nothing if not bold. 

Americans fought the British for independence, but borrowed their practice of having the head of state address government leaders regularly.

Early presidents posted letters, not showing up at the Capitol.

The U.S. Constitution mandates there be a State of the Union report. It adds that the president shall recommend measures to Congress that he judges "necessary and expedient."

Ronald Reagan started the practice of inviting special guests to the speech, like this man who dove into the Potomac River in Washington to save victims of a plane crash.
Over the years the address has evolved.

We sat down with Georgetown University government and public policy professor Mark Rom for some insight.

“Presidents have multiple purposes for the State of the Union address.  One is they want to lay out their agenda for the upcoming session. But at the same time he is laying out that agenda for Congress, he is also laying it out for the public," Rom stated.  "Congress responds to public concerns so the president also wants to mobilize public opinion to support these goals.”

The speaker of the U.S. House of Representatives formally invites the president to address both Senators and House members.  The speech is held in the House Chamber because it is larger.  Rom says that these days the speech is substantive, but also … dramatic.

“The president says what his agenda is. His backers in Congress, that is members of his party, will stand and whoop enthusiastically about this agenda.  The opponents, opposition party, will remain seated typically during those moments, cross their arms and look skeptical,” Rom explained.

It can be a time to speak of problems and offer solutions.