Republican presidential candidate Sen. Ted Cruz waves to his supporters during a rally at the Sharon Lynne Wilson Center for the Arts, Tuesday, March 29. | AP Photo Poll: Cruz leaves Trump in the dust in Wisconsin

Ted Cruz has surged to a 10-point lead over a stagnant Donald Trump in next week’s Wisconsin GOP presidential primary, according to a survey out Wednesday from the state’s most reliable pollster.

The Marquette Law School poll gives Bernie Sanders a slight edge over Hillary Clinton in the Democratic race — a result that would likely result in the two candidates essentially splitting the pledged delegates at stake next Tuesday.


In the GOP primary, the poll shows Cruz with support from 40 percent of likely voters, about 10 points ahead of Trump, who is at 30 percent. Ohio Gov. John Kasich is in third place, with 21 percent. Eight percent of likely voters are still undecided, the poll shows.

A double-digit victory for Cruz would likely result in a big delegate haul for the Texas senator: The state will award 15 delegates to the statewide winner. And a margin that great could lead to a near-sweep of the state’s eight congressional districts — each of which will award three additional delegates to the winner.

The Marquette poll is the first survey to give Cruz a significant lead in the state. The three other polls conducted earlier this month showed the race within 5 points.

The previous Marquette poll, in February, showed Trump at 30 percent among all registered Republicans — but leading, with the rest of the vote spread out among the larger field. Florida Sen. Marco Rubio was in second place, with 20 percent, while Cruz was at 19 percent. Kasich was tied with Ben Carson at 8 percent.

Trump isn’t just struggling to expand his coalition in the primary — he’s also deeply unpopular with the broader electorate. Only 22 percent of all registered voters surveyed have a favorable opinion of Trump, compared to a resounding 70 percent who view him unfavorably. And 56 percent of all Wisconsin voters say they would be “very uncomfortable” with Trump as president — more than say the same thing about Clinton (42 percent), Sanders (31 percent), Cruz (32 percent) or Kasich (12 percent).

The primary race is more stable on the Democratic side. Sanders leads Clinton, 49 percent to 45 percent, with 5 percent undecided — little change from last month, when Sanders led Clinton by a point among all registered Democrats.

Democrats award their delegates proportionally, so a narrow victory for Sanders would result in only a slight edge in pledged delegates for the Vermont senator.

The Marquette poll was conducted March 24-28 — prior to GOP Gov. Scott Walker’s endorsement of Cruz on Tuesday — interviewing likely voters in both primaries via random-digit dialing of landline phones and cellphones. The overall poll surveyed 1,405 registered voters and has a margin of error of plus or minus 3.3 percentage points.

For the Republican primary, the poll interviewed 471 likely voters and has a margin of error of plus or minus 5.8 percentage points. For the Democratic primary, there were 405 likely voters, for a margin of error of plus or minus 6.3 points.

Marquette and pollster Charles Franklin have a solid track record in Wisconsin: Their final polls accurately predicted Walker’s victory in the 2012 recall election, President Barack Obama carrying the state later that year and Walker winning a second term in 2014.