As the Washington Post reports, Alaska’s junior senator, Democrat Mark Begich, is scraping the bottom of the proverbial barrel with arguments as to why he should be re-elected. In short, he promises to be “a thorn in (President Obama’s) ass.”

The Post takes a bit of a jab at Begich: “In the Senate, Begich is a junior figure, moving through the chamber’s power structure at the speed of a mastodon trapped in a glacier. Over five years, just one of his bills has been passed into law. It renamed a courthouse in Anchorage.”

But there is a serious and broader point here: Americans usually prefer authenticity, the real McCoy, rather than the “lite” version of something. For example, when Republicans during the George W. Bush years were acting like Democrats-lite, spending money, adding huge entitlements, etc., because they believed that was the direction voters wanted the country to go (and I’m not saying they were wrong in that assessment), voters said “Hey, if we want big spending, let’s just elect the experts at that, the Democrats.” And that gave us the horror of Speaker of the House Nancy Pelosi.

Now the foot is on the other hand, and the best that vulnerable Senate Democrats can say to try to shore up support in red or purple states is “I promise I’ll disagree with Barack Obama.” But if voters really want politicians who will do that — and again I think that assessment is correct — why would they go for a Democratic “thorn-lite” when a real Republican thorn is available?

When “I’ll oppose the president of my own party” is the best argument a candidate has, he’s skating on thin (Alaskan) ice…