Through the Affordable Care Act, Obama uses a variety of means-dozens of them, actually-to attempt to bring down costs within the existing program. But he does it while retaining Medicare’s guarantee of coverage. Romney, on the other hand, explicitly refuses to entertain changes within Medicare itself. He doesn’t propose changing the way Medicare pays for care, or suggest any pilot programs or any incentives to lower costs. Instead, he hopes that that competition with private insurers is all that’s necessary to bring those costs down. If that doesn’t work, his plan will shift more and more of the expense onto the seniors themselves. One approach says we can shape this program to make it work as well as possible and use it to leverage the kind of changes we’d all like to see in the broader health care market. The other says if we just get government out of the way, the market will produce optimal results on its own. The Obama approach includes some uncertainty; improving on a large and complex government program isn’t easy, and it’s likely that some of the reforms in the ACA will work better than others. So it’s possible it won’t succeed. But if Romney was right, the private insurance market would already be outperforming Medicare. And we know that hasn’t happened.Beyond that, I might add, Obama’s approach uses Medicare’s massive leverage to execute cost-saving improvements in how the entire health-care system operates, while the Romney/Ryan approach exposes Medicare much more than it is today to the cost pressures of the private market-place, which have boosted, not restrained, prices, even as it makes tomorrow’s retirees more “individually responsible” (i.e., stuck with the bill for) their health care.