Ron Reagan is discounting Bill O'Reilly's newest book, Killing Reagan, calling O'Reilly a “snake oil salesman” who doesn't care about truth.

O'Reilly's Killing Reagan, the latest in his ongoing series with co-author Martin Dugard, was released on September 22. Their previous books have repeatedly been called out for shoddy scholarship.

“Bill O'Reilly is not somebody who as far as I can tell really invests a lot of time or energy in the truth,” Reagan told Media Matters in a phone interview on Monday. “He's a snake oil salesman, he's a huckster, he's a carnival barker, but that's about it. He's not a journalist. I don't consider him to be that. Is it annoying when anyone writes crap about your parents or your family members, loved ones? Yeah.”

The president's son also criticized many of today's conservative commentators and presidential candidates for invoking his father's name and legacy to support their own views.

“It bothers me, yes, that they're using him for whatever purpose they have in mind,” Reagan said. “They'll just take whatever idea they have and they'll just slap his name on it and hope that that just gets them over. Certainly I don't feel good about that. I don't pay all that much mind to it any more than I pay to, say, Bill O'Reilly's forays into history.”

Reagan, who was 22 when his father was shot in 1981 by John Hinckley, Jr., said he was not aware of the book about the failed assassination attempt, telling Media Matters, “I didn't know my father was the next one to get killed in Mr. O'Reilly's universe.”

According to Reagan, he's “not interested in his theories,” so he does not plan to read O'Reilly's book.

Reagan thinks his father would have had a harsh view of prominent conservative media figures. “I can't imagine that he wouldn't have found them bigoted, homophobic and all the rest as they appear to be,” he said. “I also think that he would find people like Bill O'Reilly and Sean Hannity to be just hucksters. I don't think that he would be impressed by their sincerity or their intellect. I don't think that either one of them are really serious about what they say.”

He also criticized the candidates for pandering to conservative media figures, something he says his father would not have done.

According to Reagan, “Unlike a lot of politicians today, he didn't need the imprimatur of some talk show host, he was very much his own man. He wouldn't be worrying about what Rush Limbaugh said about him.”

The president's son said it's wrong for many of the Republican candidates and right-wing media figures to assume Reagan would have agreed with them.

“Most of the people who claim to be his followers have never even met him, never knew him,” the junior Reagan said. “You see that a lot. Did Ted Cruz hang out with my father? I don't think so. The broader issue I think is the Republican Party now has become a very different animal than it was when my father was president. It doesn't make sense either to start bringing up my father -- who left office a quarter of a century ago -- and styling yourself as you'd like people to think after him. They're always asking themselves 'what would Ronald Reagan do?' in these circumstances and miraculously it always turns out that he would do exactly what they were intending to do; so clearly they're just using him to sort of validate whatever policy they have in mind.”

He also agreed with the view of many observers that his father would not be welcomed into the Republican Party of today.

“That's true if you compare his record then with their rhetoric and policies now, it would seem that Ronald Reagan really wouldn't be a good fit,” he said. "That's absolutely right. I don't see him being more conservative now than he was then. I don't see him if he had lived to be 100 and whatever continuing a progression in his politics that mirrors that of the Republican Party today -- it is a mean-spirited party.

“But more than that it's a party that's no longer a legitimate political party because it's forsaken any interest in governance. This is a party that when Obama came into office, of course, [party leaders] famously met ... and said 'we're going to oppose everything he does, even if it's things that we want to do, we're going to oppose it because the best way to get him out of office in four years is to just make it seem as if he can't do anything.' So that's what they set out to do, screw the country. They didn't care about that.”

Asked about Reagan's immigration views, for example, his son said, "He had no hostility towards Latinos, Hispanics. He admired their culture, enjoyed it very much ... There was no kind of xenophobia of that type in him. He would've I'm sure said, 'we have a right to control our borders' and things like that and if there were issues with people just flooding across the border that that was something that needed to be dealt with but he was not hostile toward these people ... He would have been looking for a sensible, workable solution for this, not relying on the kind of jingoistic, bigoted stuff that you hear coming from Donald Trump and some of the others."

On gun violence, Reagan thinks his father would disapprove of how far to the right the National Rifle Association has driven the party on the issue, saying, “This is an instance where they have simply moved so far beyond him that he couldn't stomach it anymore ... I think he would see the NRA as becoming extremist and I think he would probably recognize as well, I'd like to hope so anyway, that they're really just shills for the gun industry.”

Reagan also thinks his father would not have approved of Republicans' recent threats to shut down the government: “I think he'd be appalled actually at ... the idea of shutting down the government because you want to defund Planned Parenthood. What are these, children? As if government doesn't do anything good.”