When has Cruz won an open primary?
If they are only polling Republican voters, I think Trump has a very good shot to win.
I think Cruz has only won ONE open primary state I believe (Oklahoma OT Texas). The rest of his wins were closed primaries or caucuses.
As soon as I found out that the Marquette poll showing Cruz leading by 10 was only of likely Republican voters, I immediately discounted the poll knowing Wisconsin is an open primary and also knowing Trump has lots of blue collar union democrat and independent supporters who will be voting for him in Wisconsin.
The GOP primary race in Wisconsin is more than likely a dead heat there.