What source are you quoting that says he lost 300,000 facebook friends?
I've seen it reported numerous times, starting on Friday night. I didn't realize the assertion was controversial. Maybe it's just a rumor.
My bad. I misspoke. It's not Facebook friends, it's Twitter followers. I'm not sure what the Facebook losses are, but Ted Cruz lost about 300,000 Twitter followers over the weekend as a result of his shameful naked opportunism:
That's about a 25% loss of Twitter followers in one fell swoop.
No matter how you want to spin it, that's significant.