Sen. Ted Cruz is standing his ground, refusing to apologize to Paul Pelosi for sharing conspiracy theories about the hammer attack … even after seeing the shocking police video of what went down.

The Senator was at Reagan National Airport when we got his reaction to the body cam showing David DePape smash Pelosi in the head with a hammer — he called it the “utterly unacceptable” actions of a “deranged lunatic.”

Although he was quick to condemn DePape … Cruz got much quieter when we asked if he’d apologized to Pelosi for supporting, or at the very least, promoting theories suggesting there was something shady about the details of the attack.

In one instance, he reshared a tweet that shot holes in the idea DePape was “some kind of militant right winger” … despite reports he actually had been posting on far-right political blogs.

As we reported, DePape attacked Pelosi with a hammer inside his and then-House Speaker Nancy Pelosi‘s SF home.

DePape — who’s since been charged with attempted murder — told the FBI he was planning on shattering the Congresswoman’s kneecaps, because he thought she was a liar.

Despite all that information, the body cam and surveillance videos showing DePape smash a back door to enter the Pelosi home … Sen. Cruz is refusing to even acknowledge an apology might be appropriate.