1) To make to appear holier or better than it actually is.
2) To present something or someone as perfect when it/he/she obviously isn't.
3) To gloss over someone's faults - e.g. what a political party does to its own candidate.
Guy 1: Bro. CNN said that Hillary has a spotless record and decades of dedicated service.
Guy 2: Don't fall for Clinton News Network, man... They try to angelicize her.