Regarding violence at Donald Trump rallies and Ted Cruz's interview about that violence:
It is commonsense that no one can force you to be violent but he is saying Trump made them do it.
Senator Cruz used the word "encouraged" numerous times in the video that you're referring to, never the word "made". Did you by chance watch the video?
It is just lame trying to blame Tramp for their lunacy.
Being that you're not of this world, I doubt that you're aware of all of the violence Donald Trump has incited at his rallies:
Incite:
to stir, encourage, or urge on; stimulate or prompt to action:
to incite a crowd to riot.
All the times Trump has called for violence at his rallies
"The audience hit back. That's what we need a little bit more of."
"In the good old days this doesn't happen because they used to treat them very, very rough."
"Try not to hurt him. If you do, I'll defend you in court, don't worry about it."
"Knock the crap out of them."
"Maybe he should have been roughed up."
Etc.
Hear it in Trump's own words:
http://mashable.com/2016/03/12/trump-rally-incite-violence/#YTA8oqgKyiq5
That being said: Many Trump supporters are justifiably angry at what's going on in this country. Unfortunately they're channeling their anger through violence and supporting the wrong candidate who will only stick with the status quo if elected President.
what happened to freedom of speech you are so proud of?
That's exactly what Senator Ted Cruz was talking about in the very first part of the video (which I doubt that you viewed).