WASHINGTON — As Rep. Charles Rangel prepares to push a one-year fix of the alternative minimum tax, Senator Clinton is running as fast as she can from his larger, $1 trillion tax plan.

Pressed at the Democratic debate on Tuesday, Mrs. Clinton refused to back his idea to impose a 4%–4.6% surtax on individuals making more than $150,000 a year, and she stated explicitly that she would not make his plan a part of her campaign.

The New York senator repeatedly praised the chairman of the House Ways and Means Committee for being “courageous” in putting forward his proposal, but she kept her distance from what Republicans have already derided as the “mother of all tax hikes.”

“I’m not going to get committed to a specific approach, but I applaud Chairman Rangel for beginning the conversation,” she said. Aiming for a specific answer, moderator Tim Russert then asked her if she would campaign on his plan.

“No,” she replied. “That’s Charlie Rangel’s plan, and I support and admire his willingness to take this on.”

The Harlem Democrat, who has endorsed Mrs. Clinton’s candidacy, is proposing the surtax to pay the estimated $840 billion cost of repealing the minimum tax, which has increasingly hit middle class taxpayers despite being intended only for the nation’s top earners. Mrs. Clinton said she supports reforming the AMT, but she has refused to say how she intends to pay for it.

Mr. Rangel did not return calls yesterday.

While Mr. Rangel’s broad proposal may languish, the Ways and Means Committee will take up a separate bill today aimed at preventing the AMT from subjecting 23 million Americans to a tax hike next year. The so-called one year patch is also contentious, however, because Mr. Rangel has proposed to pay for it by more than doubling the tax rate on “carried interest” profits earned by managers of hedge funds and private equity firms.

That has sparked an intense lobbying effort, and sources yesterday said some Democrats on the committee, including Rep. Joseph Crowley of Queens, were pushing to exempt venture capital and real estate firms from the tax hike over concerns that it could hamper job growth. Mr. Crowley is likely to be wary of publicly opposing Mr. Rangel. An aide said last night that he supports increased “tax fairness” but is also “mindful that the code takes into account job creation.”

Complicating the matter is that the House speaker, Rep. Nancy Pelosi, is said to be opposed to any carve-out, according to an industry source.