WASHINGTON ��" A beaming President Barack Obama on Tuesday signed a historic $938 billion health care overhaul that guarantees coverage for 32 million uninsured Americans and will touch nearly every citizen's life, presiding over the biggest shift in US domestic policy since the 1960s and capping a divisive, yearlong debate that could define the November elections. Celebrating "a new season in America" ��" the signature accomplishment of his White House so far and one denied to a line of presidents before him ��" Obama made the massive bill law with an East Room signing ceremony. He was joined by jubilant House and Senate Democrats as well as lesser-known people whose health care struggles have touched the president. Obama scheduled back-to-back events to mark the moment, with much of his White House audience, as well as hundreds of others, gathering at the Interior Department for Act II immediately after the signing. "With all the punditry, all the lobbying, all the game-playing that passes for governing here in Washington, it's been easy at times to doubt our ability to do such a big thing, such a complicated thing, to wonder if there are limits to what we as a people can still achieve," Obama said, his remarks interrupted by applause after nearly every sentence. "We are not a nation that scales back its aspirations. We are not a nation that falls prey to doubt or mistrust. We don't fall prey to fear. We are not a nation that does what's easy. That's not who we are. That's not how we got here." The president's victory lap proceeded even as Congress labored to complete the overhaul with a companion measure making changes to the main bill that were a condition of House Democrats' approval. Debate on that bill, also passed Sunday by the House, could begin Tuesday in the Senate. Not everyone was cheering the new law. Attorneys general from 13 states filed suit to stop the overhaul just minutes after the bill signing, contending the law is unconstitutional. Florida Attorney General Bill McCollum took the lead in the lawsuit, joined by colleagues from South Carolina, Nebraska, Texas, Michigan, Utah, Pennsylvania, Alabama, South Dakota, Louisiana, Idaho, Washington and Colorado. Other GOP attorneys general may join the lawsuit later or sue separately.