MILWAUKEE (WTAQ) - Lots of Wisconsinites are still undecided about who to pick in Tuesday’s Republican U.S. Senate primary.

A new Marquette Law School poll released Wednesday afternoon shows that 21 percent of 519 likely voters have not chosen one of the four GOP candidates, with only six days until the election.

The new poll gives Tommy Thompson a wider lead than he’s had in both previous Marquette polls and other independent surveys. Thompson has 28 percent support, to 20 percent for Eric Hovde, 18 percent for Mark Neumann, and 13 percent for Jeff Fitzgerald.

Thompson’s lead is well beyond the poll’s margin of error of 4.4 percent.

When the undecided voters were pressed to choose somebody, a-third of them chose Thompson and another quarter mentioned Hovde. 7 percent refused to say anything.

In head to head matchups, Thompson led Democratic nominee Tammy Baldwin 48-43. Baldwin led Fitzgerald 45-40. She led Hovde 44-41. And Neumann was tied with Baldwin at 44-apiece.

Poll director Charles Franklin said all the head to head results were within their margins of error.