President Bush and the Republican-controlled Congress launch an intensive drive this week to enact Medicare (search) prescription drug legislation, hoping that a GOP government can end years of partisan gridlock.

On the eve of a debate likely to resonate in the 2004 elections, administration officials and lawmakers agree a formidable array of obstacles must be cleared before legislation can reach Bush's desk.

They involve policy - whether to offer all Medicare beneficiaries the same drug benefit, for example. They also include ideology - how large a role the government should play - and political considerations - how aggressively to seek Democratic support, particularly in the Senate.

But by their own words, Bush and GOP leaders put the issue high on the legislative agenda, and the president is expected to actively press for the measure when he returns from a European trip.

"Medicare is a binding commitment of a caring society," the president said in his State of the Union message last winter. "....Leaders of both political parties have talked for years about strengthening Medicare. I urge the members of this new Congress to act this year."

Majority Leader Bill Frist (search), a Tennessee Republican who is the Senate's only physician, intends to have legislation on the floor for a vote at mid-month. "It will be hard work, but in the end I know we can approve a plan to improve the current system, to strengthen it, to guarantee all seniors access to prescription drugs in a plan that can best meet their health care needs," he said.

Speaker Dennis Hastert seems no less determined. As the House debated Bush's tax cut legislation late into the night last month, the Illinois Republican was discussing prescription drug legislation in his Capitol office with lawmakers crafting a plan of their own. "This has always been one of the speaker's top priorities," said his spokesman, John Feehery.

As a political issue, Medicare has always favored Democrats. But Republicans used their majorities in 2000 and again in 2002 to push prescription drug legislation through the House - and to blunt Democratic campaign attacks designed to win the votes of older voters. Both times, legislation died in the Senate in partisan brawls.

This time, Republicans have set aside $400 billion over the next decade for the effort.

In general, the emerging GOP legislation is expected to create a new system of private insurance to deliver drug coverage to millions of Medicare recipients, with the government underwriting part of the cost. Seniors would pay a combination of premiums, co-payments and deductibles at levels yet to be determined. Above a certain point - $2,000 in last year's House bill - the individual would pay all drug expenses. At a still higher level - $3,700 in the bill that passed the House last year - insurance would pick up the tab.

Low-income beneficiaries would be subsidized heavily.

As part of the overall drug debate, Senate Republicans, in particular, are embracing the administration's proposal to create an alternative to the current government-run Medicare. It would be similar to preferred provider organizations that are commonplace in the private insurance industry. Beneficiaries could choose between the existing program or the new one, which is expected to offer more generous health care benefits.

All seniors could receive some type of drug coverage, although the administration favors a more liberal benefit for those willing to move away from the traditional Medicare program.

On the Senate Finance Committee, where the first votes are likely to be taken next week, GOP sources say most Republicans agree with Bush on that point.

Some Republicans on the panel want an equal benefit for all seniors, though. That could also be key to gaining solid Democratic support for the legislation, and Frist's influence will be pivotal on this point, according to aides in both parties.

Another key issue is the method for providing coverage. Democrats generally prefer a government-run benefit. Their legislation, drafted to accomplish that, received 52 votes last year, a majority but short of the 60 needed to overcome Republican procedural objections.

There were compromise talks on the issue in the days following the vote a year ago, of creating a system of private insurance, with the government guaranteeing a benefit as a last resort.

The prospects are complicated in the House, as well.

While the general bill is expected to be similar to the one that passed last year, senior lawmakers are considering a plan to limit the so-called catastrophic coverage that higher-income beneficiaries receive.

If incorporated into legislation, some Republicans say the provision would inject the concept of "means testing" into the Medicare debate, with coverage linked to a person's income. The program historically has provided a uniform benefit regardless of the beneficiary's economic status.

Democrats have strongly resisted such proposals, and Republicans concede a political risk would be involved.

Also complicating the House debate is an effort by a small group of lawmakers on the Commerce Committee (search) to produce their own alternative.

Several sources, who spoke on condition of anonymity, said it would offer Medicare beneficiaries a drug card, similar to a credit card, that could be used to purchase prescription drugs. The card would cost $30 a year, and the government would give each senior who buys one a fixed amount of money to spend. That would range from unlimited funds for those at or below the poverty level, to $100 for those at $22,450 a year and higher.