It’s hard to imagine, given that the National Football League is a multi-billion-dollar-a-year enterprise and America’s favorite sport by a wide margin, but the NFL has a public relations problem.

Last week a veterans group — American Veterans, or AMVETS — tried to purchase an ad in the Super Bowl 52 game program that asked people to “#PleaseStand” during the national anthem.

The league, which has seen much of its 2017-18 season consumed by controversy over players’ National Anthem protests, was having none of it. League officials rejected AMVETS’ ad on the grounds that it violated the NFL’s policy on political speech.

NFL spokesman Brian McCarthy, in explaining the league’s decision, said football has “never been a place for advertising that could be considered by some as a political statement.”

League commissioner Roger Goodell also cited the league’s policy against ads that carry a political message in explaining why the NFL rejected the ad.

The problem is that the NFL and team owners have already made allowances for political speech before and during its games.

There’s nothing wrong with the NFL giving air time and a huge public platform to players who choose to kneel during the national anthem. We believe, like many others, that those actions were offensive and wrongheaded. But players are still entitled to exercise their right to free speech.

But, as AMVETS National Commander Mario Polk said in response to the NFL’s decision: “Freedom of speech works both ways.”

Here’s more from Polk: “We respect those who chose to protest, as these rights are precisely what our members fought — and in many cases, died — for.”

Polk says the AMVETS ad was “a simple, polite request that represents the sentiment of our membership ...” when it comes to anthem protests.

We agree. And frankly it’s refreshing to see a group of people — veterans no less — willing to engage in a conversation about this controversial topic without calling anyone un-American or demanding they be drawn and quartered for exercising their rights.

But what about AMVETS’ rights? The NFL, which has intentionally made military pageantry and symbolism a keystone of its brand, couldn’t help but get in the way of a reasonable and dignified response to players’ anthem protests.

There’s a phrase to describe what’s going on here — and again Polk, in his letter, hits the nail on the head: “corporate censorship.”

If the NFL is trying to convince people that it isn’t taking sides in this debate, it’s failing miserably.

The league “encourages” players to stand but doesn’t make them; it allows them to kneel, and in kneeling make a political and social statement. This from an organization that hands out fines if players don’t wear the proper socks and shoes on the field.

It does, however, feel entitled to silence the voices of hundreds of thousands of veterans who would like to encourage players to stand.

Not call for them to be fired; not question their values or integrity as Americans. All AMVETS — which boasts 250,000 members nationwide and is dedicated to providing scholarships, helping veterans find employment and reintegrate into society after their deployments — wanted to say was “Please Stand.”

For a league that has spoken at-length about its understanding that players are making a “complex” statement by protesting, the NFL is showing remarkable disinterest in veterans’ statements how people should behave during the national anthem.

When it received AMVETS ad proposal the league had an opportunity to prove it really is interested in equality and civil discourse.

Instead, it laid bare its own blatant hypocrisy.