What in the story leads you to believe a "ruckus" was caused?
Sounds like the political opponents to McCain's surrender of our sovereignty were not welcome is all. Not surprising as McCain is trying to position himself as the great leader for President.
This illustration gives people a reason not to get behind his run for President.
Thus, the very unkind welcome.
As I read it, a dozen or so Minutemen were in the office making demands. Only those who're still licking the ground these vigilantes walk on could possibly see this as anything other than a disruption.