A 2010 IBD/TPP Poll found that 45% of doctors would at least consider leaving their practices or taking early retirement as a result of the new health care law. And, an online survey by Sermo.com, a sort of Facebook for physicians, found that 26% of physicians in solo practices were considering closing. Of course, not every doctor who told these polls that he or she would consider leaving the field will actually do so. But if even a small portion depart, our access to medical care will suffer.

In fact, we have already seen the start of this process in Massachusetts, where Mitt Romney’s health care reforms were nearly identical to President Obama’s. Romney’s reforms increased the demand for health care but did nothing to expand the supply of physicians. In fact, by cracking down on insurance premiums, Massachusetts pushed insurers to reduce their payments to providers, making it less worthwhile for doctors to expand their practices. As a result, the average wait to get an appointment with a doctor grew from 33 days to over 55 days.

Promising universal health coverage is easy. But what does universal coverage mean if you can’t actually see a doctor?