The new documentary about First Lady Melania Trump might not win an Oscar at next year's Academy Awards ... but it seems her fans will loyally defend it -- because the Rotten Tomatoes audience score is through the roof.

"Melania" came out in theaters Friday ... and early reviews show as sharp a split as any between the Democrat and Republican parties.

At the time of publishing, critics gave the doc just a 12% on Rotten Tomatoes -- put into context, just 2 of the 17 uploaded critic reviews are positive.

Two critics -- one from the Irish Times and the other a writer for entertainment outlet Consequence -- have already likened Brett Ratner's work to that of Leni Riefenstahl ... a German filmmaker who made propaganda for the Nazis.

On the flip side, the Rotten Tomatoes audience score sits at 99% ... with many reviewers lauding Melania for her patriotism and some even claiming their theaters erupted in cheers when the flick ended. Of course, Trump supporters likely make up a majority of the opening weekend audience -- but still, the percentage is huge.

"Melania" has already generated a ton of controversy ... with Rolling Stone reporting earlier this week that production of the film was a nightmare -- with their sources alleging the production was chaotic and disorderly.

Crew members made it clear Melania herself was kind to them ... but alleged director Ratner -- who has previously been accused of sexual misconduct -- was a total tyrant on set.

Anyhoo ... with such a big divide between critics and audiences, we gotta ask -- who do you believe???