Answer by taking a quote from the following article:

Dinesh Joseph D'Souza (; born April 25, 1961) is an Indian American right-wing political commentator, author, and filmmaker. From 2010 to 2012, he was president of The King's College, a Christian school in New York City. Born in Bombay, D'Souza came to the United States as an exchange student and graduated from Dartmouth College. He became a naturalized citizen in 1991.

On July 25, 2016, D'Souza released the documentary film Hillary's America: The Secret History of the Democratic Party. The film criticizes the Democratic Party and Hillary Clinton, the presumptive (and ultimate) Democratic nominee for President of the United States in 2016.  The film was universally panned by professional film critics. On review aggregator Rotten Tomatoes, the film has an approval rating of 4%, based on 27 professional reviews, with an average rating of 1.7/10. The critics consensus on the site reads, "Hillary's America: The Secret History of the Democratic Party finds Dinesh D'Souza once again preaching to the right-wing choir--albeit less effectively than ever." On Metacritic, which assigns a normalized rating, the film has a score of 2 out of 100, based on 17 critics, indicating "overwhelming dislike". The film has the fifth lowest score of all films on the site. Peter Sobczynski wrote, "Hillary's America may well be the single dumbest documentary that I have ever seen in my life." A July 2016 review in Variety characterized D'Souza as "a right-wing conspiracy wingnut, the kind of "thinker" who takes off from Barack Obama birther theories and just keeps going, spinning out a web of comic-book liberal evil."  Other critics and figures viewed the film positively. John Fund of the National Review stated that "[the film] is over the top in places and definitely selective, but the troubling facts are accurate and extensively documented in the D'Souza book that accompanies the movie." He also called the film "intensely patriotic". On July 23, 2016, Donald Trump, who was then running as the Republican presidential nominee against Clinton, called on supporters to see the film.  On January 23, 2017 the film was nominated for five Razzies including: Worst Picture, Worst Actor (Dinesh D'Souza), Worst Actress (Becky Turner), Worst Director (Dinesh D'Souza and Bruce Schooley), and Worst Screenplay. In response to the Razzie nominations, D'Souza stated that he was "actually quite honored" and called the nominations "petty revenge" in response to Trump's election victory, also stating that "the film might have played an important role in the election." After "winning" four of the five possible Razzies, D'Souza repeated his view that the nominations were awarded in response to Trump's election victory.

What was it about?
The film criticizes the Democratic Party and Hillary Clinton, the presumptive (and ultimate) Democratic nominee for President of the United States in 2016.