Universal health insurance sounds great in principle. But what if it means having wages garnished, paying extra tax in April, paying a fine, or facing some other financial mandate?

It's a question that continues to follow Democrat senators Hillary Clinton and Barack Obama as they make their last minute pitches for Super Tuesday voters.

On the TV program "This Week with George Stephanopoulos" Clinton yesterday left open the possibility that her health care program would garnish the wages of people who didn't comply.

"We will have an enforcement mechanism, whether it's that [garnishing wages] or it's some other mechanism through the tax system or automatic enrollments," Clinton said.

She did take the idea of fines off the table, however. Fines are a feature of the Massachusetts plan signed into law by then-Gov. Mitt Romney. As a GOP presidential candidate, Romney does not support insurance mandates.

Clinton says a mandate is necessary in order to create universal coverage. Obama's plan does not cover all Americans, but he argues a mandate could force economic burdens on those who can't afford to buy insurance.

The dispute raises a difficult question. Some surveys show that a modest majority of Americans believe the U.S. should have universal healthcare. But most of them think reforms should be built around private insurance, not a government program.

But how can a privately based insurance plan achieve universal coverage without a mechanism to ensure people buy into the system?

It's a complex question, being played out in sound bites during last minute campaigning. But no matter who gets the Democrat and Republican nominations, it's sure to come up in a more substantial way in the general election.