Yesterday the American Medical Association came out against a public option for health care. And yesterday the President reaffirmed his support for it. The next weeks will show what Obama is made of - whether he's willing and able to take on the most formidable lobbying coalition he has faced so far on an issue that will define his presidency.

    And make no mistake: A public option large enough to have bargaining leverage to drive down drug prices and private-insurance premiums is the defining issue of universal health care. It's the only way to make health care affordable. It's the only way to prevent Medicare and Medicaid from eating up future federal budgets. An ersatz public option - whether Kent Conrad's non-profit cooperatives, Olympia Snowe's "trigger," or regulated state-run plans - won't do squat.

    The last president to successfully take on the giant health care lobbies was LBJ. He got Medicare and Medicaid enacted because he weighed into the details, twisted congressional arms, threatened and cajoled, drew lines in the sand, and went to war against the AMA and the other giant lobbyists standing in the way. The question now is how much LBJ is in Barack Obama.

    The big guns are out and they're firing. All major lobbying firms in Washington - many of them brimming with ex-members of Congress - are now crawling all over the Hill. Lots of money is on the table. AMA's political action committee has contributed $9.8 million to congressional candidates since 2000, and its lobbying arm is one of the most formidable on the Hill. Meanwhile, Big Insurance and Big Pharma are increasing their firepower. The five largest private insurers and their trade group America's Health Insurance Plans spent a total of $6.4 million on lobbying in the first quarter of this year, up more than $1 million from the first quarter last year, and are spending even more now. United Health Group spent $1.5 million in the first quarter, up 34 percent from the $1.1 million it spent in the first quarter last year. Aetna spent $809,793 between January and the end of March, up 41 percent from last year. Pfizer, the world's biggest drugmaker, spent more than $6.1 million on lobbying between January and March, more than double what it spent last year. It also spent nearly $3.3 million lobbying in the fourth quarter of 2008. Every one of them is upping their spending.

    Some congressional Democrats are willing and able to stand up to this barrage. Many are not. They need cover from the White House.

    The President can't do this alone. You must weigh in and get everyone you know to weigh in, too. Bombard your senators and representatives. Organize and mobilize others. And let the White House know how strongly you feel. This is one of those battles that define a presidency. But more importantly, it's one of those battles that define the state of American democracy.