The statement was posted on Robert Costa’s Twitter:
https://twitter.com/costareports/status/717537276906102784
And 538 reviewed it here:
CLARE MALONE 10:37 PM
Gone are the Iowa days of Trump the graceful loser. After losing Wisconsin tonight, his campaign put out a statement saying that Trump “withstood the onslaught of the establishment” and that “Lyin’ Ted Cruz had the governor of Wisconsin, many conservative talk radio show hosts, and the entire party apparatus behind him.” The statement went on in that manner, with Trump calling Cruz a “Trojan horse, being used by the party bosses attempting to steal the nomination from Mr. Trump.”
We can gather two things from this statement: 1) Trump is feeling Cruz’s hot breath down his neck in the fight for delegates and 2) Trump is a fan of the serial comma (long may it reign).
http://fivethirtyeight.com/live-blog/wisconsin-primary-presidential-election-2016/
Did you happen to verify that came from the Trump campaign?
It doesn’t appear on any the campaign social media that I or others can find.