The health care debate in Congress this year is beginning with the ultimate in legislative low-hanging fruit: Expanding medical coverage of poor children through SCHIP, the State Children’s Health Insurance Program — a bill President Bush vetoed twice but Barack Obama is eager to sign as soon as he settles into the Oval Office.

Advocates for national health coverage know the children’s health care debate will also serve as the first salvo in a much bigger fight, one that will determine if a more robust SCHIP is this year’s most significant expansion of health care or the first step toward a far more ambitious plan to engineer comprehensive national health coverage.

The question this time around is whether the health care industry will stay on board or go on the offensive. The insurance industry was instrumental, after all, in defeating the last major bid to remake the health care system, the 1993-94 effort captained by then-first lady Hillary Rodham Clinton .

This time, many of the erstwhile opponents of national health care plans, such as insurers and employer groups, say they’re open to a health care overhaul — and are jockeying to gain a foothold in early negotiations over health care legislation, which President-elect Obama already has flagged as a major domestic policy priority. Industry lobbyists are meeting weekly with officials from groups that supported prior reform efforts and Capitol Hill staff to work through their many differences and thrash out workable compromises.

But industry players know that no end of potential conflicts lie in wait. “We’re in the happy-talk phase of health care reform,” said G. William Hoagland, who served as an aide under former Senate Majority Leader Bill Frist, R-Tenn., and who now works as vice president for public policy at the health insurer Cigna. “We’re all in agreement that everyone should have insurance, that we should control costs, that the quality of health care should be improved. After you get that out of the way and get into specifics, then that’s when things get bogged down.”

Among the issues now awaiting resolution are whether the government should offer a public coverage plan for the uninsured that would compete with private insurers, whether employers should be required to offer (and individuals be made to purchase) insurance and — not least by any means — how to pay for an overhaul.

In the early skirmishing, both the industry and advocates for comprehensive care are marshaling major grass-roots-message efforts — even though the exact nature of those messages is still evolving.

America’s Health Insurance Plans, a trade association representing some 1,300 insurers, is planning a springtime initiative in at least 10 to 15 states, said AHIP spokesman Robert Zirkelbach. The initiative will include town hall-type meetings, similar to forums in eight cities that the group held over the summer. The organization has also launched a separate campaign Web site to promote “affordable private coverage” with “a strong safety net.” The group says the multi-million-dollar campaign is its largest in a decade. The AHIP campaign has built a database of about 100,000 members that it regularly e-mails with updates from Washington. Many recipients are industry employees or participants from the town hall forums, often invited at the suggestion of local chambers of commerce. AHIP officials working on the campaign include grass-roots coordinator Beth Leonard, who previously worked as New Hampshire state director for the presidential campaign of Democrat John Edwards, and L.D. Platt, a former aide for the National Republican Congressional Committee.

Gearing up for battle among advocates for a more robust federal role in universal coverage is Health Care for America Now, a coalition backed by left-leaning interest groups. That group staged protests at the AHIP forums and at insurers’ offices throughout the country, alleging that insurers are harming the quality of health care. Its e-mails reach about 50,000 people, although the group says it has the ability to contact about 7 million online through its member organizations.

Breaking the Logjams Early

The Obama health care team, meanwhile, launched its own grass-roots effort to engage its enormous base of supporters. At the prompting of Health and Human Services Secretary-designate Tom Daschle, Obama backers gathered at a nationwide series of “coffees” in late December to air their health care concerns and weigh proposals to overhaul the system. The Obama team is posting the results of the meet-ups online — and no doubt intends to keep its base apprised of how the planned overhaul will fare on Capitol Hill.

All this early positioning leaves lawmakers conducting a quiet outreach effort of their own, as they seek to contain the potential for the kind of all-out conflict that sank the Clinton effort by securing extensive buy-ins early on from players on all sides.

Aides to Massachusetts Democrat Edward M. Kennedy , chairman of the Senate Health, Education, Labor and Pensions Committee, have held twice-a-week meetings with a group of fewer than two dozen lobbyists and advocates representing divergent interests on the issue. The meetings are similar to sessions held by Senate Finance Chairman Max Baucus , D-Mont., who has also floated a bill that could serve as the basis for an eventual health care compromise.