It pains to me state this, but the release of Robert Mueller’s report on The Russia Thing and other matters has revealed a serious stain on the presidency of Barack Hussein Obama.

I am not for a single instant going to give Donald Trump a pass on his campaign’s involvement in the Russian hacking of our electoral system in 2016. You won’t see me offer up a “What about this?” excuse for what happened during the course of that campaign.

However, I am going to concede that all of the hacking, the interference, the blatant attack on our electoral system occurred during the final full year of President Obama’s administration.

The president and the Justice Department under his watch should have taken stern, immediate and decisive measures to stop it. They didn’t.

A CNN analysis notes that Obama was too wrapped up in the Iran nuclear arms deal he and Secretary of State John Kerry were brokering to risk angering Russian President Vladimir Putin. They wanted the Russians on our side. Yet they knew of the hacking, according to Mueller, while it was occurring in real time.

Yes, so did the Trump team. They, too, should have acted. The Trump campaign should have blown the whistle loudly on what was occurring in the moment. Donald Trump’s invitation to the Russians to look for Hillary Clinton’s “missing e-mails” tempted the Russians to the point of launching their attack on our system that very day.

But as they say, we only have one president on the job at a time. The president we had in 2016 failed to do what he should have — and could have — done to stop this attack on our sacred electoral system.

President Obama said he told Putin to “knock it off” at the time. It wasn’t nearly enough.