The Senate last night came up with another way to cajole centrist Democrats and maybe a few Republicans into backing their healthcare package.

According to Bloomberg sources, Senate leaders have proposed dropping a public option and instead expanding Medicaid and Medicare to qualify more uninsured Americans for coverage.

There are two main obstacles now before the Senate: votes and time. They need a majority of 60 votes to pass their reform package, and they need it before they break for a holiday recess. Both of these are going to be extremely tough.

And, even tougher – if the Senate manages to get the votes, they will have to combine their bill with the House version.

On the other side of the Capitol, House Leader Nancy Pelosi (D-Calif.) has said the House will not agree to anything less than the public option. No dice.

Everyone reads the news, the latest hiccups from Capitol Hill on the convoluted progress of healthcare reform, but it's hard to make sense of what's happening.

Here's a simple breakdown:

There are some 47 million uninsured Americans. Most of them are employed, with no option to buy insurance through their employer.

Healthcare is up to nearly 17 percent of the Gross Domestic Product.

Republicans and Democrats agree that something must be done.

President Barack Obama wants healthcare reform passed before the end of the year.

The House did its part by passing a 1,990-page, nearly $1 trillion bill on Nov. 7 that has been estimated to be deficit neutral over 10 years. Only one Republican in the House supported the bill.

In the Senate, it's more complicated. Democrats aren't in agreement on what healthcare reform should include, causing delays and intense bipartisan bickering. Last night's move by Senate leaders to trash the public option is a sign of the squeeze these leaders face. Between a rock and a hard place, they want this bill to pass, and they may be willing to throw the baby out with the bathwater, if need be.

What's a puzzle to me is the fear of the public option, when roughly half of America is already on some sort of government-run healthcare plan, including Medicare, Medicaid, veterans' coverage, state health plans for state workers and federal employee coverage.

Another curiosity is where campaign financing might play into this process. According to the Center for Responsive Politics, a nonpartisan group, the health insurance industry has donated $17.7 million in campaign contributions to senators taking part in the current healthcare reform debate.

Is the fear really over a public option?