What was the exact quote?
There are a bunch of links to video of Cruz blaming Trump. Not hard to find.
"What we're seeing, is we're seeing Republicans unifying behind our campaign. We're seeing Republicans coming together. This race has become a two-person race. Between me and Donald Trump. And more and more Republicans are unifying behind our campaign.”
“And I also want to mention something about the events this evening. In Chicago. This is a sad day. Political discourse should occur in this country without a threat of violence. Without anger and rage and hatred directed at each other. We need to learn to have disagreements without being disagreeable—to have disagreements while respecting human beings on the other side. Earlier today, over 30 people were arrested at one rally, and then tonight, as violence broke out, the rally was cancelled altogether. Now, the responsibility for that lies with protesters who took violence into their own hands, but in any campaign, responsibility starts at the top. Any candidate is responsible for the culture of the campaign. And when you have a campaign that disrespects the voters—when you have a campaign that affirmatively encourages violence, when you have a campaign that is facing allegations of physical violence against members of the press, you create an environment that only encourages this sort of nasty discourse.”