When the president of Ohio’s state school board posted her opposition to gun control, she used a powerful symbol to make her point: a picture of Adolf Hitler. When a well-known conservative commentator decried efforts to restrict guns, he argued that if only Jews in Poland had been better armed, many more would have survived the Holocaust.

In the months since the Newtown, Conn., school massacre, some gun rights supporters have repeatedly compared U.S. gun control efforts to Nazi restrictions on firearms, arguing that limiting weapons ownership could leave Americans defenseless against homegrown tyrants.

But some experts say that argument distorts a complex and contrary history. In reality, scholars say, Hitler loosened the tight gun laws that governed Germany after World War I, even as he barred Jews from owning weapons and moved to confiscate them.

Advocates who cite Hitler in the current U.S. debate overlook that Jews in 1930s Germany were a very small population, owned few guns before the Nazis took control, and lived under a dictatorship commanding overwhelming public support and military might, historians say. While it doesn’t fit neatly into the modern-day gun debate, they say, the truth is that for all Hitler’s unquestionably evil acts, his firearms laws likely made no difference in Jews’ very tenuous odds of survival.

‘‘Objectively, it might have made things worse’’ if the Jews who fought the Nazis in the 1943 Warsaw ghetto uprising in Poland had more and better guns, said historian Steve Paulsson, an expert on the period whose Jewish family survived the city’s destruction.

But comparisons between a push by gun control advocates in the U.S. and Hitler have become so common — in online comments and letters to newspaper editors, at gun rights protests and in public forums — they’re often asserted as fact, rather than argument.

‘‘Absolute certainties are a rare thing in this life, but one I think can be collectively agreed upon is the undeniable fact that the Holocaust would have never taken place had the Jewish citizenry of Hitler’s Germany had the right to bear arms and defended themselves with those arms,’’ former Major League Baseball pitcher John Rocker wrote in an online column in January.

After some gun advocates rallied at New York’s capitol in February carrying signs depicting Gov. Andrew Cuomo as Hitler, National Rifle Association President David Keene said the analogy was appropriate.

‘‘Folks that are cognizant of the history, not just in Germany but elsewhere, look back to that history and say we can’t let that sort of thing happen here,’’ Keene, who was the lead speaker at the rally, told a radio interviewer March 1.

Those comparisons between gun control now and under Hitler joined numerous other statements, including the one by the Ohio school board president, Debe Terhar, on her personal Facebook page in January and by conservative commentator Andrew Napolitano, writing in The Washington Times.

The comparisons recently prompted the Anti-Defamation League, a Jewish civil rights group, to call on critics of gun control to keep Hitler and the Nazis out of the debate.

The rhetoric ‘‘is such an absurdity and so offensive and just undermines any real understanding of what the Holocaust was about,’’ said Ken Jacobson, the ADL’s deputy national director. ‘‘If they do believe it, they’re making no serious examination of what the Nazi regime was about.’’

But some gun rights advocates firmly disagree.

‘‘People who fail to learn from history are doomed to repeat it,’’ said Charles Heller, executive director of Jews for the Preservation of Firearms Ownership, which has long compared U.S. gun control to Nazi tactics. ‘‘I guess if you’re pro-Nazi, they are right. But if you’re pro-freedom, we call those people liars.’’

Comparing gun control activism to Hitler is not new. In a 1994 book, ‘‘Guns, Crime and Freedom,’’ NRA Executive Vice President Wayne LaPierre wrote that ‘‘In Germany, firearm registration helped lead to the Holocaust.’’

But the history of civilian gun ownership under the Nazis, scholars say, is far more complicated than the rhetoric indicates.

After World War I, Germany signed a peace treaty requiring dismantling of much of its army and limiting weapons import and export. But many of the 1 million soldiers returning home joined armed militias, including a Nazi Party force that saw Communists as the leading threat.