Wisconsin voters know Democratic Sen. Russ Feingold very well. They know that even if they disagree with him on an issue, Feingold will stand firmly on his principles rather than pander to whatever is politically popular.

Voters don’t know Feingold’s Republican challenger Ron Johnson very well. In fact, Wisconsin voters wouldn’t know Johnson if he bit them.

Most of them had never heard of Johnson until a few months ago. Many still have not.

Despite that, state Republicans decided Johnson would make a dandy candidate for the U.S. Senate because he’s a millionaire willing to spend lots of money to become a senator.

Most voters need a little more than that to go on, however. And finding out what Johnson thinks about anything is a lot harder than you might imagine.

Since he’s never held public office, there is no record of where Johnson stands or what he believes. His entire public career apparently consists of making a couple of speeches at tea party rallies.

But it gets even more complicated than that. Every time the Feingold campaign manages to nail down something Johnson has said that demonstrates a clear political difference from Feingold, Johnson either reverses his previous position or denies he ever believed what he said in the first place.

It’s become a pattern.

This first came up on the issue of oil drilling. There are good reasons to wonder where Johnson stands on oil drilling since he’s disclosed he owns stock valued between $116,000 and $315,000 in BP, the oil company giant whose blown-out well spewed hundreds of millions of gallons of oil into the Gulf of Mexico.

(Johnson also has given conflicting accounts as to whether he will or won’t sell his BP stock.)

In an interview with the political website WisPolitics, Johnson was asked whether he wanted to open up more of the United States to oil drilling, specifically either the Great Lakes or Alaska’s Arctic National Wildlife Refuge.

Johnson’s response: “We have to be realistic … and I think we have to get the oil where it is, but we need to do it responsibly.”

After Feingold began running television ads attacking Johnson’s willingness “to hand over the Great Lakes to the oil companies,” Johnson suddenly developed a catastrophic hearing deficiency.

Johnson claimed he didn’t hear the portion of the question when the interviewer asked: “Would you support drilling in the Great Lakes, for example, if there was oil found there?”

Now Johnson says he doesn’t support allowing oil companies to despoil Lake Michigan, a more conventional position for a Wisconsin politician.

Taking Both Sides—Again

The same pattern of Johnson taking both sides of an issue has arisen around gun rights.

It’s an issue on which Feingold’s core beliefs often conflict with those of his most liberal supporters. But no one can accuse Feingold of simply pandering to Wisconsin gun owners for political purposes.

Feingold supported the rights of gun owners before he ever had a political career. As a UW-Madison student in the ’70s, at the same time he was developing his opposition to open-ended foreign wars, Feingold wrote his senior thesis on the Second Amendment, concluding that the Constitution guaranteed gun ownership as an individual right.

It was the broadest possible interpretation, one that the Supreme Court itself would not embrace until decades later under the gung-ho pro-gun Roberts court.

Anyone concerned about the proliferation of guns had to admire Johnson’s political courage in calling for more restrictions on guns before a conservative group in Jefferson County.

Asked what gun restrictions he would support, Johnson said: “You know, like we license cars and stuff… I don’t have a real problem in minimal licensing and stuff. I mean I don’t.”

Those of us who consider Johnson’s position common sense were happy to hear a Republican candidate brave enough to express it.

But not so fast. Once again, as soon as Feingold began running ads criticizing Johnson’s position, Johnson completely reversed himself.

Johnson issued his new, improved position on guns: “I do not, nor will I ever, support licensing or registration of firearms.” Wonder who that guy was who did.

Johnson explained that taking the opposite position was just a mistake made by someone who was not “a slick politician” like Feingold who “twists words for a living.”

It’s the guiding theory of the tea parties that there is nothing more weaselly than a career politician. They argue that anybody off the street would be preferable to a career politician who will say anything to get elected.

Yet, no one in Wisconsin has ever been confused about where Sen. Russ Feingold has stood on any issue.

It’s the non-politician Ron Johnson who keeps putting out positions on both sides of the issues until he can figure out which one might attract the most votes.