Melania Trump has made combating bullying one of her main priorities in the White House - the thrust of her "Be Best" initiative.

In excerpts released ahead of Abrams' remarks, she calls the shutdown a political stunt that "defied every tenet of fairness and abandoned not just our people, but our values". As long as the rank-and-file voters are with Trump, Republicans in Congress will be afraid to openly oppose him, but the minute he loses that support, or even the perception of it, the growing divisions will spill into the open.

Republican strategist and former White House official Raj Shah said the speech offered Trump a chance to turn the page.

For Trump, the focus on reaching across the aisle is a tacit admission from the White House that Trump may need a course correction if he is to win re-election.

Senate Minority Leader Chuck Schumer of NY accused Trump of "blatant hypocrisy", saying the president may want to talk about unity on Tuesday but "spends the other 364 days of the year dividing us".

With Trump occupying the spotlight, those in the growing field of prospective candidates now serving in Congress are hoping that their chosen State of the Union guests will send him a message, create their own headlines or both.

Senator Angus King, an independent, told MSNBC potential for bipartisan action over opioids, HIV and infrastructure could be derailed "if he throws down the gauntlet and gives us another lecture on the wall". John Cornyn, R-Texas, said he remains hopeful Congress can resolve the dispute by February 15, when funding for some government agencies runs out. Expect a chilly response in the chamber from Democrats as he talks about what he again says would be a "wall".

But broader cooperation seems unlikely, especially if Trump pushes forward with the border wall. Despite the shutdown, the USA economy added a robust 304,000 jobs in January, marking 100 straight months of job growth. Trump wants to bring US troops back from those countries, but many GOP lawmakers warn threats in both places are too great to do so.

In a weekend interview with CBS, Trump said efforts to defeat the IS group were "at 99% right now".

That means a "unity" speech would not be a simple declaration that the opposition party needs to come around to the president's way of thinking about everything from the economy to immigration to national security and foreign policy.

Trump, in excerpts of his address, defended his moves, declaring: "Great nations do not fight endless wars".

Other issues in tonight's State of the Union: A second summit with North Korea's Kim Jong Un, trade with China and America's robust economy. If he builds his State of the Union around the wall, he will be building it around an issue with little constituency outside the most pro-Trump factions of the Republican party.

Meanwhile, some White House officials are trying to spin the upcoming speech as positive and unifying. "The family of a couple who were killed by an undocumented immigrant; a police officer and a synagogue member who survived a mass shooting in Pittsburgh; a woman who was granted clemency by President Trump; and a sixth grader who has been bullied because he shares the commander in chief's last name".

"Anybody who's sitting there with their arms folded ... looking like they sucked on ... lemons, that's not on him because he's calling for unity, he's calling for working together", White House counselor Kellyanne Conway told Fox News of Democratic lawmakers.