And now, for something new, John McCain is attacking Barack Obama over his big-spending ways:

The text of this new advertisement, for those who don't want to sit through the cilp, goes like this:

When our economy's in crisis, a big government casts a big shadow on us all. Obama and his liberal Congressional allies want a massive government, billions in spending increases, wasteful pork. And, we would pay--painful income taxes, skyrocketing taxes on life savings, electricity and home heating oil. Can your family afford that? 

I have no idea whether this is an actual television advertisement or one of those spots, distributed over the internet, designed to generate media coverage. I also have no idea whether this ad resonates politically.

But the arguments themselves are worth scrutinizing because they are consistent with McCain's broader rhetoric. He and his supporters are constantly attacking Obama as an irresponsible tax-and-spender. Today in Iowa, as a matter of fact, McCain is lashing out at the "big spending, greedy, do nothing, me first, country second crowd in Washington."

If you follow politics closely enough to read this publication, then you're already familiar with the dishonesty of McCain's claim on taxes. The vast majority of taxpayers would get a larger break under Obama's reforms than they would under McCain's. Only the very wealthiest Americans would see more tax relief from McCain. (For more on this, see here and here.)

So let's look instead at the other charge--the one that almost nobody challenges, not even Obama himself, because the subject remains so politically troublesome for Democrats. It's this idea that Obama wants to go on a spending binge--and that this binge will leave Americans worse off.

Is that really so?

Look closely at what Obama has proposed this election cycle. According to various press accounts, Obama's top four spending initiatives are, in order, his plans to achieve universal health coverage or something close to it; to invest in alternative energy development; to increase foreign aid; and to boost spending on education, particularly early childhood education. (Wonky side note: Not all of this "spending" is actually spending per se; sometimes it comes in the form of tax breaks.)

Health care is by far the most expensive of these proposals. Obama's aides calculate it would cost $65 billion a year. (Count me among those who think the final plan will cost even more.) The rest are in the range of $10 to $25 billion a year. McCain and, more generally, conservatives would have you believe that money is simply wasted. By that, presumably, they mean it's being spent in ways that don't benefit you--or in ways that are inefficient.

That's simply not the case.

Anybody who has no health insurance, has too little health insurance, or has health insurance that might not be around tomorrow will benefit from Obama's health care plan, which--if enacted--would guarantee coverage, with generous benefits and at affordable prices, to every single American regardless of income and pre-existing medical conditions. What's more, creating a universal health system--or even moving towards one, if that's all Obama's plan ends up doing--would be good for the economy. It would help put in place mechanisms, like institutions that scrutinize new treatments for effectiveness, that would help tame runaway medical spending. It would let people move more freely from job to job, which should--at least in theory--allow them to maximize their productive potential. And it would provide businesses with a great deal more predictability about their employee health costs, something most corporate executives would appreciate.

Obama's investments in alternative energy would have a similar effect. It would create jobs, particularly in areas of the country hard hit by manufacturing layoffs, and--over time--it would reduce the dependence on petroleum. Again, that's something that benefits everybody, not just individually but on a grand, collective scale as the easing of the energy crunch rippled through the economy. As for education, it's hard to think of investment that has greater potential to produce higher economic growth over the long term than making sure all kids know how to read, write, and count. On an individual level, parents confident of high quality public schools in their neighborhood won't have to contemplate shelling out tuition for private school--or moving to more expensive neighborhoods.

(Foreign aid, I suppose, is the exception here. Justifying it purely on economic grounds is tough. But there are plenty of valid reasons to increase foreign aid--not least among them, the potential to ease suffering and buy some goodwill in areas that might otherwise be fertile ground for tomorrow's terrorists.)

Conservatives like McCain naturally believe that the free market, left to its own devices, would handle these tasks better. And they're entitled to their opinions. But the fact that people want--and need--these sorts of initiaitves ought to make everybody else skeptical of such arguments. If the free market could provide everybody with affordable health care, why would we have 45 million Americans uninsured--and another 25 million (at least) underinsured? If the free market could wean us off peteroleum dependence, why are we all now sweating out $4-a-gallon gas prices? If it could educate every youngster, why are so many kids growing up illiterate?

There's a reason McCain uses the word "spending." It's easier to oppose than universal health care, investment in green technology, and good schools. Here's hoping the voters grasp that they mean the same thing.

--Jonathan Cohn