After Sessions became one of the first members of Congress to endorse Trump this February, he became an adviser on almost every major decision and policy proposal Trump made during the campaign: -A top Sessions aide helped Trump communicate his immigration policy -Sessions chaired Trump national security advisory committee -Sessions advised Trump on who to choose for vice president.

These are two positions that could put him at odd with the president he'll serve: Trump has expensive plans that involve significant spending, like $1 trillion on an infrastructure program -- and he campaigned on a strong non-interventionist worldview (often claiming, inaccurately, that he opposed the Iraq War before it started).

He's a climate change skeptic: Here's Sessions in a 2015 hearing questioning Environmental Protection Agency's Gina McCarthy: "Carbon pollution is CO2, and that's really not a pollutant; that's a plant food, and it doesn't harm anybody except that it might include temperature increases."