President Barack Obama's drive to overhaul the U.S. healthcare system has created opportunities and risks for members of both political parties in the Democratic-led U.S. Congress.

As Obama prepares a high-stakes address to Congress on Wednesday, here's a look at some of most important lawmakers with an eye toward the 2010 election, when the entire 435-member House of Representatives is up for re-election, along with 38 of the 100 senators.

SENATE MAJORITY LEADER HARRY REID AND HOUSE SPEAKER NANCY

PELOSI

Unlike Reid, Pelosi has said that a final plan must include a government-run insurance program to provide competition to private insurance companies. Reid seems more open to compromise to pick up Republican support, but he risks losing fellow Democrats if he abandons the public option.

As the top two Democrats in Congress, Reid and Pelosi will be pinned with much of the blame if lawmakers fail to pass a significant bill. But they will likely be able to take much of the credit if such a measure becomes law with public support.

Back home in Nevada, Reid faces a tough re-election race. Pelosi is expected to easily win another term in her liberal California district.

SENATOR CHRIS DODD

Dodd's political fate may be tied to healthcare. Seen as the most vulnerable Senate Democrat, his prospects could improve dramatically if he is able to help craft a healthcare bill that becomes law.

He had been expected to succeed the late Edward Kennedy as chairman of the Senate health committee and help lead the charge. But a Senate aide told Reuters Dodd would not take that post and would remain chairman of the Senate Banking Committee as it takes on the huge task of regulatory reform.

SENATE REPUBLICAN LEADER MITCH MCCONNELL AND HOUSE

REPUBLICAN LEADER JOHN BOEHNER

Both have objected to Democratic legislation, complaining it would cost too much and give the government too much control. Yet with Americans favoring reform, neither wants to be seen as an obstructionist.

Both are expected to keep up their attacks against any Democratic-backed plan and push for a bipartisan solution. In the end, Democrats will likely get scant Republican support.

Like most congressional leaders, Boehner is expected to easily win re-election. McConnell isn't up for re-election next year, but hopes to cut the Democrats' majority.

SENATOR CHARLES GRASSLEY

Grassley is a Republican member of The Gang of Six senators that has sought to find a bipartisan deal. Yet with a reputation for being unpredictable, Grassley became increasingly critical of the effort in recent weeks following town hall meetings nationwide that showed public anger at an expanding federal government. Democrats have essentially given up on winning support from the 75-year-old Iowan, who seems set to win re-election.
SENATOR OLYMPIA SNOWE

Another member of The Gang of Six. A moderate, Snowe isn't up for re-election next year, and was one of three Republicans who backed Obama's $787 billion stimulus package in February.

She has put her reputation on the line again in an effort to find a bipartisan healthcare agreement. She's been in talks with the White House on a possible scaled-back bill. It would not include the public option favored by many Democrats. But it would permit the option to be added if insurance companies failed to make specific reforms to increase accessibility and affordability.

Snowe, if she signs on, might be able to pull along another Republican and certainly would give political breathing room to more centrist Democrats to support the plan.

SENATE FINANCE COMMITTEE CHAIRMAN MAX BAUCUS

Baucus, a centrist Democrat, has been criticized by liberal for being too willing to give up on a government-run option. He has worked closely in the past with Grassley and wants a bill with some Republican support. The death last month of Senator Edward Kennedy, a Democratic lawmaker seen as a consummate dealmaker, has increased the pressure on Baucus to deliver. He won re-election easily in 2008.

SENATE BUDGET COMMITTEE CHAIRMAN KENT CONRAD

Conrad also belongs to The Gang of Six. He's crafted a potential compromise of his own. Instead of the public option, Conrad wants to create nonprofit cooperatives that would provide medical coverage to its members. His proposal is expected to be part of any bill produced by the Finance Committee. The proposal appeals to many rural lawmakers long familiar with co-ops, which have been used to provide electricity to rural areas and by farmers to buys supplies and market their products. He isn't up for re-election until 2014. (Writing by Thomas Ferraro, additional reporting by Donna Smith, Editing by Stacey Joyce and Jackie Frank)

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