Ezra Klein has been writing great posts, including this one today, taking apart Mitt Romney’s “budget” plans. As he notes, the numbers in Romney’s budget proposals just don’t add up. Either Romney is going to make cuts in things he says he’ll protect, or he’ll blow up the deficit instead of his claims to cut it; or he’ll slash spending severely on popular programs, the kind that if you pressed him on it he’d surely deny intending to cut at all. Such as, say, spending on veterans.

The thing is, we’ve seen this exact sequence before on the taxes side. Remember this one? Either Romney’s tax plans would add to the deficit contrary to his claims of revenue neutrality, or he wouldn’t really cut upper income tax rates the way he says he would or he’s going to dramatically raise taxes on everyone except for the very rich.

Now, there are a couple of ways you can handle this. One way is to give Romney credit for the parameters he sets most specifically, which leads to “Romney will slash spending on veterans by 40 percent!!!” and “Romney will raise taxes on the middle class!!!” And those aren’t exactly unfair claims, since they derive from what Romney has said.

Or you can just wind up where Klein does today: “I’m not sure what alternative there is, exactly, except to say, as clearly as possible, Romney’s budget plan is a fantasy, and it will never happen.”

The thing is: it’s not true that all politicians do this sort of thing. People have hit Romney for lacking specifics, but the problem here is that he is very specific at times, giving us exact numbers for certain tax rates and for federal spending as a percentage of GDP, and those specific commitments really do imply all the horrors that Democrats are going to attack him for. If Romney was merely saying that he wanted to reduce overall federal spending, and reduce tax rates while eliminating deductions, he wouldn’t have this problem.

So the real choice here is whether to give Romney credit for the goodies he wants to promise — in which case he should have to take the blame for the costs — or just treat everything he says as junk. There’s no real correct answer to that, but watch for the Romney campaign to shift back and forth as they try to have it both ways.