What is Hollywood filmmaker Ron Howard -- who recently criticized President Trump in a Twitter message -- going to do when the president inevitably wins reelection later this year? That's what Andrew Pollack, father of one of the 17 victims of the Parkland, Fla., high school massacre, wants to know.

In a New Year’s Day tweet, Howard -- the 65-year-old former child star who went on to direct "Splash," "Apollo 13," and a long list of other films -- lamented that President Trump was a "morally bankrupt ego maniac."

RON HOWARD TRASHES TRUMP ON TWITTER, CALLS HIM A 'MORALLY BANKRUPT EGO MANIAC'

Pollack, whose daughter Meadow Pollack was killed in the Feb. 14, 2018, massacre at Stoneman Douglas High School, responded Friday.

“Let’s see here Ron…," Pollack wrote, "President Trump gave up his billion dollar lifestyle to save this country.

“President Trump donates his ENTIRE salary. President Trump was loved by Hollywood before he became a Republican. What are you going to do when he wins again in 2020?”

Howard, whose career began as Opie Taylor on the classic television sitcom "The Andy Griffith Show," and later performed in the 1973 film "American Graffiti and in the 1970s comedy series "Happy Days," was responding to a critic who said it's "only negativity from Hollywood & Democrats" when it comes to Trump. The critic claimed the Oscar winner had downplayed the successes of the president's economy.

"In the entertainment industry many who have known/worked w/ Trump think that while his reality show was fun and ran a long time, he’s a self-serving, dishonest, morally bankrupt ego maniac who doesn’t care about anything or anyone but his Fame & bank account & is hustling the US," Howard wrote.

Howard later went on to defend the entertainment industry after another Twitter user accused Hollywood of being "amoral elitists who hate average Americans."

"Honestly not what I’ve seen or felt throughout my lifetime from the vast majority of people in the entertainment business," Howard responded. "In fact, I gotta say it’s the opposite. Most are not from LA or NY to begin with. Now Trump is both an elite and a reality show star."

Pollack became an outspoken advocate for school safety since the Parkland shooting, and has written a book detailing his own investigation into the events that led to the massacre.

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In "Why Meadow Died: The People and Policies That Created The Parkland Shooter and Endanger America's Students," Pollack discusses his views on gun control, why he blames Democratic policies for his daughter's murder, and precautions that parents can take to ensure the safety of their children.

During an interview on "Fox & Friends" in September, he said he had met with Trump five times since the shooting and applauded the president’s initiation of a federal school safety commission to investigate what steps need to be taken to ensure safety in schools across the country.

Fox News’ Joseph A. Wulfsohn and Yael Halon contributed to this report.