President Donald Trump will deliver his first formal State of the Union address tonight before a joint session of Congress.

Speaker Paul Ryan (R-Wis.) presides in the House chamber of the U.S. Capitol, with Vice President Mike Pence beside him in his constitutional role as president of the Senate. Congress, Supreme Court justices, the Joint Chiefs of Staff and all but one of the president’s Cabinet members — the so-called designated survivor— will attend.

A designated survivor is a cabinet-level official appointed during the State of the Union every year in order to maintain the continuity of government should a “calamity” happen while all other members of the federal government are in a single location.

The White House announced announced last week that the president would release his complete immigration policy "framework" before the State of the Union, so this will almost certainly be a centerpiece. According to a White House official, Trump’s speech will be one of unity as he tries to appeal to a fiercely divided Congress.

Trump will also take a page from his speech on Friday at the World Economic Forum in Davos, Switzerland, and talk about strong economic growth in the U.S., as well as the benefits of the recently enacted tax changes and an America-first trade policy. In view of the recent nuclear threats from North Korea, the Republican leader will highlight a national security policy of “peace through strength,” the White House official said. He also plans to use the opportunity to reveal the details of his long-awaited infrastructure plan.

Trump, however, is infamous for veering from prewritten speeches, so there is always the possibility that the State of the Union will vary from the expected topics and methods of delivering them.

Trump's State of the Union Address will begin at 8 p.m. Central time on Tuesday, Jan. 30.