Backing
Supporting
noun, verbal noun
You embrace someone to keep them standing. You're backing and supporting this person, so no matter what happens you've gotta keep them on their feet.
擁立 is a formal word for backing someone up for a position, usually in politics or organizations. It's used when people unite to promote or nominate someone as a leader or as a political candidate.
This is a jukugo word that uses the on'yomi readings of the kanji. You should be able to read this on your own.
どうせ出馬者を擁立しようとしているだけだろう。
I'm sure that they are just trying to support the candidate.