An early showdown over health care reform is expected on the Senate floor by week's end now that Majority Leader Harry Reid has unveiled the Democrats' bill.

Republicans vow a protracted struggle to block the legislation and deny the president a victory that would cap a tumultuous first year in office.

The Democrat's $849 billion measure is designed to remake the nation's health care system, relying on cuts in future Medicare spending to cover costs -- as well as on higher payroll taxes for the well-to-do. There's also a new levy on elective cosmetic surgery. The bill would extend coverage to most Americans and bar denial due to pre-existing conditions.

Republican leader Sen. Mitch McConnell says Americans know that higher premiums, tax increases and more government do not add up to reform.