It's interesting for me to see how strongly some of you guys from America responds to any form of invasion of personal space, and certain rules laid down by the government.
I work at an airport and regularly get patted down, as well as when I travel in my own spare time. I don't mind it. If it increases security, then by all means go for it. I know the rules before I go, and if I don't like the smell, then I'll stay away.
I also think that it's a bit insulting to a lot of people suggesting that the TSA are pedophiles, or some other form of perverts, just because they do a proper pad down, even on a kid. You know it's going to happen, your kid won't be any less "pure" afterwards (Their doctor might also see their sacred parts by the way, oh no!), and since human ethics can be pretty low, normal families with kids could be used (paid or forced to) to traffic drugs etc. The TSA have procedures, they follow them. Besides that, you would be surprised how 'stupid' (Maybe not stupid, but ignorant to the rules) some people are, especially with first time flyers etc. (This applies everywhere... In the middle eastern countries people will try to bring live chickens and that which are MUCH worse on the plane for their religious trip to Mecca).
Sure there might be some power tripping TSA agents, like there are in most jobs, but if you don't make an effort to single yourself out, you'll probably be overlooked in the crowd of literally thousands of other people going through every day.
If you want to call first amendment rights or whatever you use over there, then stay at home where you make most of the rules. If you go into public space with written rules, and are expecting to fly on a private airline (where they make the rules) then you should follow them. Don't be a snowflake at the cost of others...
That's my thoughts any way, sorry for rambling...
To OP: Enjoy Vegas! I hope to go there myself one day.