Hovde, who entered the race in March with almost zero name recognition statewide, has spent more than $1 million of his own money on ads already. The investment seems to have paid off: In the poll he trails Thompson by 30 to 27 percent, with former Rep. Mark Neumann (R-Wis.) at 20 percent.

Internal polls should always be taken with a grain of salt, but these are good numbers for a candidate few had heard of two months ago. The poll shows Hovde's name recognition among likely Republican primary voters jumping from 27 percent in February to 71 percent today.

But the 99 percent name identification for Thompson in the poll, 92 percent for Neumann and 71 percent for Wisconsin Assembly Speaker Jeff Fitzgerald (R), also in the race, indicates the poll may have only found die-hard Republicans who are closely following the race — and the 27 percent name identification for Hovde in February, before he even jumped in, further suggests that.

The poll of 600 likely Republican primary voters was conducted by Whit Ayres, a top Republican pollster, and his firm North Star Research. They were in the field from May 6 to 8 and the poll has a margin of error of plus or minus 4 percent.