A new Marquette University Law School poll out Wednesday shows Ted Cruz has pulled ahead of Donald Trump in Wisconsin.

The same poll also shows Bernie Sanders has expanded his slight lead over Hillary Clinton.

The poll shows Cruz now has support from 40 percent of likely Republican primary voters, that's a 21 percent jump from last month.

While Donald Trump remains at 30 percent, and Ohio Governor John Kasich has climbed to 21 percent.

On the Democratic side, Bernie Sanders' lead over Hillary Clinton has grown by three points since last month. The poll shows Sanders has support from 49 percent of likely democratic primary voters, Clinton has support from 45 percent.

The poll’s director, Charles Franklin, says Ted Cruz's skyrocket to the top of the Republican field is the biggest surprise.

Franklin said, "I think Cruz really does show he is consolidating the support. I think the Governor's (Scott Walker) endorsement, I think Speaker (Robin) Vos' endorsement, talk radio, Charlie Sykes, all of those things are coming together to send a really strong signal to Republican voters in this state."

In the race for Wisconsin Supreme Court, Justice Rebecca Bradley has increased her lead over appellate court judge JoAnne Kloppenburg. Bradley has a 41 percent to 36 percent lead.

The poll also shows Senator Ron Johnson is narrowing the gap against former senator Russ Feingold. Feingold’s lead is down to five points, 47-42.

Governor Scott Walker's approval rating is rebounding after taking a hit during his run for president. It’s now sitting at 41 percent, up three points from last month.