Perhaps the silliest idea of the current election cycle is that somehow Republicans lost the presidency in 2008 and might lose the presidency this cycle because the media — and even many Republican leaders — went easy on Barack Obama by not exposing vulnerabilities which would destroy him if they were better known. As Greg Sargent pointed out this morning, whatever dubious merit this idea had in 2008, it’s clearly nonsense in 2012. After two years of the first Obama campaign and almost four years of an Obama presidency, it’s just not plausible that new revelations, especially concerning those from before his presidency that supposedly show who the “real” Obama is, will have any effect.

That’s the theory, and we’ve had a very nice test of it the last few weeks. After all, we’ve had the big rollout of “2016,” a movie that has done quite well . . . but meanwhile Obama has moved steadily up in the polls. “2016” claims that “Love Him Hate Him You Don’t Know Him,” but it turns out, as sensible analysts have said, that most Americans actually do have as good a sense of Obama as they’ll ever have, barring something new in the present that changes their opinions.

Nor are any of the “revelations” we’re being told about anything new, at any rate. “Redistribution”? That was Joe the Plumber. Not exactly an obscure, suppressed story in 2008.

And that’s even without Ed Kilgore’s addition that the Romney/Ryan ticket isn’t one that’s apt to be helped by applying that same standard to themselves. After all, Republicans are all supposed to forget everything Mitt Romney said or did before, oh, last August, while swing voters certainly aren’t supposed to remember Paul Ryan’s enthusiasm for ending Social Security and Medicare as we know it.

So basically the “vetting” argument doesn’t make sense in theory, has constantly proven a bust when attempted, and has the added problem that it may lead to questions about the Republican ticket — who are far more vulnerable to new information since most voters have much less to go on right now. Why, then, does it persist?

I think David S. Bernstein (my brother, the longtime reporter on conservatives) has this one right: Part of the answer is that the Romney campaign has very different incentives than do many of the people urging them to focus on this nonsense. In the “movement conservative marketplace” stuff such as Obama’s sympathy to terrorists or the idea that Democrats are deliberately attempting to create a nation of deadbeats who will therefore vote for them or Obama’s dubious “associations” are all great products which the customers line up to purchase (either directly by, for example, buying books, or indirectly by listening to and watching shows which then sell ads).

And the problem is twofold: not only does that mean that very loud voices are constantly telling the Republican ticket to say things that don’t actually have any good chance of working in an electoral setting, but also that people who live in that world — GOP campaign professionals and donors and even candidates included — are constantly being told that those things should work.

But step outside that world, and it’s painfully obvious that it’s all an illusion.