LOL!
The bikers wouldn’t have been drinking till AFTER the meeting. DUI checkpoints would not have stopped any bikers BEFORE the meeting.
Well, maybe a couple of the meth heads ...
Point was, they do those without declaring martial law.
And not everyone at a dui checkpoint has had a drink now, have they?
If you know who you wanted, and they did, you could find them pretty easily at just such a checkpoint...
But, again, bystander safety was of least concern.