A lot of commentators think so, including Paul Krugman of the New York Times. According to experts, Clinton's health care plan, by calling for mandated coverage, would cover millions more Americans than Obama's plan, which, except for children, does not mandate coverage for all Americans.
This is how Krugman puts it in his February 4th column:
But as I’ve tried to explain in previous columns, there really is a big difference between the candidates’ approaches. And new research, just released, confirms what I’ve been saying: the difference between the plans could well be the difference between achieving universal health coverage — a key progressive goal — and falling far short.
Specifically, new estimates say that a plan resembling Mrs. Clinton’s would cover almost twice as many of those now uninsured as a plan resembling Mr. Obama’s — at only slightly higher cost.
Krugman explains that last comment by later citing in his column to a study by a MIT professor:
Mr. Gruber finds that a plan without mandates, broadly resembling the Obama plan, would cover 23 million of those currently uninsured, at a taxpayer cost of $102 billion per year. An otherwise identical plan with mandates would cover 45 million of the uninsured — essentially everyone — at a taxpayer cost of $124 billion. Over all, the Obama-type plan would cost $4,400 per newly insured person, the Clinton-type plan only $2,700.
That doesn’t look like a trivial difference to me. One plan achieves more or less universal coverage; the other, although it costs more than 80 percent as much, covers only about half of those currently uninsured.
Further, Obama attacks Clinton's plan using right-wing style language attacking Clinton's plan on the issue of mandates. Krugman compares this to the infamous Harry and Louise ads of the 1990s that were created by the insurance industry:
You see, the Obama campaign has demonized the idea of mandates — most recently in a scare-tactics mailer sent to voters that bears a striking resemblance to the “Harry and Louise” ads run by the insurance lobby in 1993, ads that helped undermine our last chance at getting universal health care.
What Krugman worries about is that even if Obama later decides that there should be mandates, his campaign's rhetoric against mandates will be used to defeat such a plan in Congress.
Obama's supporters like to claim that he practices a cleaner, more progressive form of politics, but using right-wing scare tactics against Clinton's health care plan doesn't strike us as particularly progressive.