At a Trump rally??..no, this kind of behavior wouldn't bother me. First off, they aren't patriotic. They are nationalistic, chest thumping lemmings. Feeling safe is irrelevant. I feel sick that this is what these people (and people like you) have brought this country to.
At a golf tournament? Yes, this kind of behavior is boorish and uncalled for. You want to cheer. Fine. Dispense with the constant USA!!..USA!!. It's a golf match, not an international soccer match. But what I've seen over the last two days of catcalling and taunts, calling for a miss (before a shot is taken or a putt made), and just the general level of ignorance of the crowds, it makes me want to see Europe pull off an upset just to shut the crowd up.
And yes, when the Ryder Cup is held in Europe, their fans cheer raucously for their team. It can be just as intense, if not more than over here. But there's a difference. Over there, the Americans are not subjected to nearly the behavior and treatment that I've seen the Europeans subjected to this week.