Tonight, the U.S. Senate will try to begin debate on health care reform. Note the word "try." Because of Senate filibuster rules, it will take votes from 60 of the Senate's 100 members just to start the discussion on the Senate floor.

Work on such a critical issue ought to be done in the open, where all Americans can hear the alternatives and the arguments pro and con. An open process gives each side a fair chance to make its case to the public.

But it's possible the filibuster threat will drive the health care discussion back behind closed doors, where Senate Democrats will try to work out something that can clear the 60-vote hurdle. If that happens, it will be just one more example of the petty, partisan bickering that impairs our country's ability to address its problems.

There are valid concerns to be raised about the Democratic health care proposal, just as there is a strong case for action to make sure all Americans have affordable, effective health coverage.

Opponents of the Senate Democrats' reform plan may well be right when they say it doesn't do enough to control health care costs. The bill is as fat as a phone directory and it's about as hard to understand as a physics textbook. It also counts on big savings in Medicare that may not materialize.

All the more reason to launch the Senate's debate. Let the nation hear the arguments and have a thorough look at the Republicans' alternative.

They offer an approach focused on individual choice, using tax credits or subsidies in hopes of getting more people to buy coverage and make healthier lifestyle choices. That approach may well leave people exposed to financial catastrophe, and it definitely leaves the average person at the mercy of health insurance companies.

A few Democrats still hold out hope for converting the entire health care system to a Medicare-for-all model -- universal coverage with the government paying almost all the cost. Let's hear that case too.

In a country as huge and as diverse as ours, it's no surprise that there is no national consensus behind a particular approach to health care reform. There never will be. Democracy is a messy, inefficient and contentious process.

Big political decisions that were controversial at the time -- creating Social Security in 1935, Medicare in 1965, civil rights legislation of the 1960s -- are now almost universally accepted. Majority rule has a way of working out in the end, but it works best as an open, honest contest of ideas.

The U.S. Senate has long been known as "the world's greatest deliberative body." These days, it's better referred to as "the world's greatest obstructionist body." Nothing gets done unless 60 votes are there to break the minority's procedural stranglehold on any given subject.

Senate opponents don't even have to do what a filibuster is supposed to require -- talk, talk, talk, so nothing else gets done and the other side gives up. These days, the mere threat of a filibuster is enough to scare off the other side.

There's a saying in politics: When you don't have the votes, you say, "Let's debate." When you do, you say, "Enough debate. Let's vote."

In this case, though, just starting the debate requires a vote -- a supermajority vote. All 40 Senate Republicans would rather stifle the health care debate than risk losing on the Senate floor.

Sixty senators need to step up and begin the Senate debate on health care reform -- and may the best proposal win.