Greenwald stands accused by Democrats of being a closet Libertarian, having spoken in front of the Koch Brothers' Cato Institute.  To the consternation of critics, Greenwald has spoken more than once at a Socialism Conference where he nearly gushes warmth and enthusiasm. Greenwald has also advocated many positions libertarians would hate, such as opposing cuts to Social Security and Medicare.
Greenwald was one of three speakers at the 2014 YAL (Young Americans for Liberty) National Convention; the other two were Ron and Rand Paul. Greenwald does hold Dr. Paul in some esteem, but he laments the man's checkered past:
There are very few political priorities, if there are any, more imperative than having an actual debate on issues of America’s imperialism; the suffocating secrecy of its government; the destruction of civil liberties which uniquely targets Muslims, including American Muslims; the corrupt role of the Fed; corporate control of government institutions by the nation’s oligarchs; its destructive blind support for Israel, and its failed and sadistic Drug War. More than anything, it’s crucial that choice be given to the electorate by subverting the two parties’ full-scale embrace of these hideous programs.
I wish there were someone who did not have Ron Paul’s substantial baggage to achieve this.
His opinion of Baby Doc is on point, too.
As Ed Brayton has noted, many conflate Greenwald's narrow approval of select Paul positions with endorsement (something Brayton himself is often accused of). Brayton labels Greenwald's analysis of Paul as "brilliant," declaring that it "perfectly explains why I have said many of the things I’ve said about Ron Paul…it also speaks strongly to the question of how liberals should handle libertarians and libertarianism as a whole." 
So potent is this poison that no inoculation against it exists. No matter how expressly you repudiate the distortions in advance, they will freely flow. Hence: I’m about to discuss the candidacies of Barack Obama and Ron Paul, and no matter how many times I say that I am not “endorsing” or expressing support for anyone’s candidacy, the simple-minded Manicheans and the lying partisan enforcers will claim the opposite.
In point of fact, his only political endorsements have been given to left-wing Democrats, e.g. Russ Feingold and Rush Holt. In 2016, Greenwald published his interview of progressive Democrat, Tim Canova, who was then challenging incumbent Debbie Wasserman Schultz in the Florida primaries. Greenwald linked to a site where contributions to Canova's campaign might be made. Canova is controversial for being a militant Zionist, He opposed the Iran nuclear deal, accusing Wasserman Schultz of being "in on it", He later changed his position on it, stating that he supported "its full implementation," only to go back to being against it shortly after.