https://law.marquette.edu/poll/wp-content/uploads/2016/03/MLSP34Toplines.pdf
This was conducted prior to Scott Walker's endorsement of Cruz.
GOP:
Cruz 39.6
Trump 30.4
Kasich 21.4
Democrat:
Sanders 49.2
Clinton 44.9
General:
Clinton vs. Cruz 44.2 - 44.2
Clinton vs. Kasich 39.2 - 48.1
Clinton vs. Trump 47.1 - 36.6
Sanders beats all 3.
This was conducted prior to Scott Walker's endorsement of Cruz.
GOP:
Cruz 39.6
Trump 30.4
Kasich 21.4
Democrat:
Sanders 49.2
Clinton 44.9
General:
Clinton vs. Cruz 44.2 - 44.2
Clinton vs. Kasich 39.2 - 48.1
Clinton vs. Trump 47.1 - 36.6
Sanders beats all 3.