Immigration: Making the case for a ‘crisis’ (again).

Immigration policy dominated the president’s agenda during his second year in office, and most likely will again during the third. Mr. Trump has consistently tried to make the case that there is a “crisis” — of crime, drugs and human trafficking — at the border with Mexico, an emergency that can be dealt with only by building a border wall.

The president is also likely to call for a legislative solution to address the so-called Dreamers, younger immigrants who were brought to the United States illegally as children and have no criminal record. This is one area of possible cooperation with Democrats, but there are significant disagreements about details.

Mr. Trump is not expected to veer from his demands for billions of dollars in funding for border security, including some kind of barrier. Congressional negotiators from both parties are trying to hammer out a deal on border security, but Democrats have been adamant that they will not agree to money for Mr. Trump’s wall, and the president has been pessimistic about the chances of Capitol Hill coming up with an agreement that meets his approval.

Still, he is not expected to use the address on Tuesday to declare a national emergency, which potentially would enable him to construct additional barriers along the border using presidential authority.

An appeal to the Republican base on abortion?

White House officials said the president is also likely to talk about abortion and the “fundamental importance and respect for human life.” Mr. Trump’s evangelical supporters, who fervently oppose abortion, have been the bulwark of his political base.

He might also talk about China’s program of forced abortion and sterilization, and perhaps even efforts in the United States to ease some abortion restrictions, such as a contentious amendment regarding late-term abortions being considered by the legislature in Virginia.

A rationale for reducing troop levels in Syria and Afghanistan.

Mr. Trump has called for a substantial withdrawal of troops from the war in Afghanistan, where the United States military has been fighting for more than 17 years. But he has encountered uncharacteristic pushback from Republicans about taking troops out of Syria.