Reid, who led efforts to shepherd the $940 billion legislation through the Senate, is facing a tough reelection battle this fall. He spoke at several Democratic county conventions in northern Nevada on Saturday.
“The most important thing we've done for the country and the world is health care,” he said according to the Nevada Appeal.
Republicans have warned Democrats to use the healthcare law, upon which the public is divided, during the fall campaigns at their own peril.
Democrats have countered, saying that the healthcare law is one of their greatest achievements, comparing it to the passage of large, popular entitlement programs such as Social Security and Medicare.