I’m very pleased the Romney campaign is attacking President Obama for cronyism (see the ad above) — establishment Republicans are typically hesitant to go after subsidy-sucklers because it comes across as “anti-business.”

But there’s a very obvious problem when Romney knocks Obama for subsidizing Obama bundlers: Romney, unlike George W. Bush, Barack Obama, and John McCain, refuses to disclose the names of his bundlers — volunteer fundraisers.

Dave Weigel makes this point at Slate:

We know that Obama’s bundlers stood to gain if, say, Solyndra did well, because Obama’s campaigns have disclosed the names of bundlers. But the Romney campaign hasn’t disclosed the names of bundlers.

So, this morning, the Romney campaign made Ed Gillespie available to talk about the new line. “Do you want to have an economy in which political appointees in D.C. make decisions about where tax money is spent based on who contributors were in the last cycle?” asked Gillespie, rhetorically.

NBC’s Peter Alexander asked the natural follow-up: Would Romney’s campaign reveal who its bundlers were? That way, you know, people could determine, now or in 2013, whether they were benefiting from Romney policy.

Gillespie basically dodged the question.

Obama’s greatest weakness, in my eyes, is the cronyist tendencies of his subsidize-and-regulate economic philosophy, combined with his directly related failure to live up to promises of transparency. If Romney is going to attack on this front, he has to be much cleaner than Obama. Bucking the custom of GOP nominees, and refusing to disclose bundlers, defangs Romney’s argument.