Robert J. Spitzer is Distinguished Service Professor of Political Science at SUNY Cortland, and the author of five books on gun policy, including "Guns across America" and "The Politics of Gun Control." The views expressed here are solely the author's. Read more opinion on CNN.

(CNN) One hallmark of Donald Trump's presidency has been his penchant for contradicting himself . One example of his inconsistency has been his back and forth on gun control. The President's apparent U-turns have left the nation spinning in the aftermath of successive horrific mass shootings.

Ever since 2016, Trump has been locked in a tight embrace with the NRA and the gun community, so his periodic endorsements of new gun laws suggest that, like most of the country, he has been genuinely moved by the anguish and suffering of the victims and their families after each tragedy. Even the gun community and NRA members support new gun measures like uniform background checks and red flag laws. Widespread support for these measures suggests that this is a pivotal moment for the national gun debate. Trump should heed those signs and, for once, his feelings.

In his 2000 book "The America We Deserve," Trump wrote , "I generally oppose gun control, but I support the ban on assault weapons and I support a slightly longer waiting period to purchase a gun." After he launched his presidential campaign, Trump declared himself a " Second Amendment person ," said he carried handguns " sometimes a lot " and called gun and magazine bans " a total failure. " By May 2016, the National Rifle Association endorsed Trump, who enthusiastically embraced the gun-rights agenda.

Since the election, he's reverted to being a waffler-in-chief on guns. This came most sharply into focus after the Parkland high school shooting in February 2018. In an emotional meeting with the survivors and their families, Trump told them he would " do something about this horrible situation.

In a follow-up meeting with congressional leaders, Trump said he would "take a look" when Sen. Dianne Feinstein called his attention to a new proposal to ban assault weapons. According to Minnesota Sen. Amy Klobuchar, who also attended the meeting, Trump said he supported universal background checks. The President also promoted the idea of raising the gun purchase age from 18 to 21

In perhaps his most surprising declaration, offered in response to concerns about people who might commit violence, Trump said , "I like taking guns away early. Take the guns first, go through due process second."

What happened to President Second Amendment? Trump's own response may be the explanation: that he was genuinely moved by the "heartbreaking stories" of shooting survivors, prompting him to vow that "It's not going to be talk like it's been in the past." But the feelings don't last—maybe because a stronger force negates Trump's sentimental moments.

Just four weeks after the Parkland shooting, Trump spoke with NRA leaders and proceeded to walk back any promises to push for gun control. He decided to appoint a commission, headed by Education Secretary Betsy DeVos, to examine school violence. To no one's surprise, its report recommended no new gun laws.

And here we are again. In the evening after the horrific El Paso shooting, Trump crashed a wedding at his private golf club instead of delivering a public address. The Dayton mass shooting rocked the nation just hours later, and Trump responded to the tragedies in the following days by endorsing "common sense, sensible, important background checks." But then Trump backed away from his initial statements on background checks after a lengthy phone call with NRA chief Wayne LaPierre, sources told CNN

One might think that to avoid looking like a noncommittal flip-flopper, Trump would choose to either stick with the NRA line or decide once and for all to push for gun control proposals which are not only supported by a wide majority of Americans but even by a majority of NRA members. Instead, he resembles an NRA poodle on an elastic leash that yanks him back when he strays.

Why does Trump always return to the NRA line? A plausible answer is found in the fact that Trump is the only president to have spoken at the NRA's annual convention every year, where he is met with a hero's reception. It may well be that Trump is driven by the adoring crowds even more than fealty to gun rights or a desire to rake in campaign money. In his first 30 months in office, he's held more than 60 such events.

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