Hours after a jubilant House Democratic leadership rolled out what they hope will be landmark health care legislation, the gritty work of actually passing it began.

Leaders ran into a firewall of resistance from moderate Democrats and vulnerable freshmen grousing over the measure’s provisions to tax the wealthy and small businesses. Some Members also want more cost cutting, even if it leaves more people uninsured.

Immediately after the bill was introduced, Speaker Nancy Pelosi (D-Calif.) personally wooed conservative Blue Dog Democrats, but they didn’t budge.

“I think that there’s still a long ways to go,— Rep. Allen Boyd (Fla.) said. “Many of us wish we would wait and do this after the Senate acts, and we’ve communicated that to leadership.—

And Rep. Jared Polis (Colo.), meanwhile, was circulating a draft letter among freshman Democrats to Pelosi opposing the $544 billion income tax surcharge on the wealthy, arguing it would hit many small businesses and manufacturers.

“Especially in a recession, we need to make sure not to kill the goose that will lay the golden eggs of our recovery,— Polis wrote. “By concentrating the cost of health care reform in one area, and in one that will negatively affect small businesses, we are concerned that this will discourage entrepreneurial activity and job growth.—

That objection was gaining steam Wednesday among freshmen and others from wealthy suburban districts, as business groups stepped up their attacks.

The tax hikes causing heartburn include a surcharge on families making more than $350,000 a year, a tax on employers that do not provide health insurance and a tax on the uninsured.

But the concern is not just with the substance of the proposal. Some Members fear they will take a tough vote on a tax hike that will not survive the Senate and they think it is merely a placeholder to get through the House. “There’s no reason we shouldn’t be voting on bills that aren’t at least very similar,— one senior Democratic aide said.

Complicating matters more is the question of what would replace the all-in-one approach to raising more than a half-trillion dollars. “There is a school of thought that they can’t find another politically tenable solution or one that actually works,— one Democratic leadership aide said.

Hoping to avoid a repeat of the bruising process that produced the narrowly passed climate change bill last month, leaders are fanning out to the rank and file to try to sell this package early and allay concerns.

A blitz of closed-door sessions with different Democratic Caucus groups that began last week continued into this week. Pelosi met Tuesday with the Congressional Progressive Caucus and the Blue Dogs. On Wednesday afternoon, she took time out to try to build support in the liberal blogosphere by submitting to a live question-and-answer session on the liberal Crooks and Liars blog, and then she headed into back-to-back huddles with the freshman and sophomore classes along with Majority Leader Steny Hoyer (D-Md.).

House Majority Whip James Clyburn (D-S.C.) met Tuesday with the Congressional Black Caucus, on top of smaller skull sessions with others. And among the groups that Education and Labor Chairman George Miller (D-Calif.) met with: the Small Business Caucus. “There’s been an uncountable number of meetings on this,— freshman Rep. Chellie Pingree (D-Maine) said.

But among those with the biggest problems, the diplomacy is so far yielding little progress. Rep. Mike Ross (D-Ark.), the chairman of the Blue Dogs’ health care task force, said he hasn’t yet been swayed by meetings with Pelosi or President Barack Obama.

He said the revised health bill did little new to address Blue Dogs’ desire for cutting costs over new taxes and protecting small businesses.

“There’s some minor changes,— Ross said, noting a plan to exempt small businesses below $250,000 in revenue from new taxes. But Ross said the changes don’t go far enough and threaten small businesses who already cannot afford insurance.

“If we’re not careful about how we structure this, not only are these employees not going to have health insurance, they’re not going to have a job either,— he said.

“It still looks like a budget buster,— said Rep. Jim Cooper (D-Tenn.), who complained that despite the $1 trillion cost it would still fail to cover every American.

But Democratic leaders defended the bill and vowed concerns would be fully vetted. Democratic Congressional Campaign Committee Chairman Chris Van Hollen (Md.) said charges that small businesses will face big new taxes are false, and he said Members would be armed with the facts on how the bill would cut costs.

“Right now every American pays $1,200 a year in a hidden tax because they are paying for people who are uninsured,— Van Hollen said.

Blue Dogs plan to make a stand in the Energy and Commerce Committee markup Thursday, where they could kill the bill unless their amendments are adopted.

Other gripes remain. Members of the Congressional Tri-Caucus — made up of the Asian Pacific American, black and Hispanic caucuses — want to see a stronger anti-discrimination clause in the bill. And Del. Donna Christensen (D-Virgin Islands), co-chairwoman of the CBC Health and Wellness Task Force, said her group wants the bill to go further in addressing health care disparities in minority populations.

Energy and Commerce Chairman Henry Waxman (D-Calif.) said he will meet with Ross, along with others, and plans to amend the bill again tomorrow himself.

But he urged them to work to pass the bill instead of tearing it down.

“Can a bunch of Members bring a bill down? Yeah. Then what? … Democrats have a lot at stake in this legislation, the president has made this his No. 1 priority,— he said. “We’re going to have to come together.—

Jennifer Bendery contributed to this report.