Donald Trump's backing up traffic -- not on the streets of NY -- but outside one of his favorite NYC restaurants.
The President-elect -- along with Melania, Ivanka, Eric, Donald Jr., and son-in-law, Jared -- paid 21 Club a visit Monday night, but now when he goes it requires an intense security search ... of every other patron.
We got video as a bunch of hungry customers waiting in line to get wanded and patted down by Secret Service. Last month Trump slipped away from the press pool and hit up the fancy midtown Manhattan spot ... pissing off reporters.
Customers could've been the ticked ones this time -- although everyone seemed cool.