The US Congress approved a package of final changes to President Barack Obama's landmark health care overhaul Thursday, and Obama dared Republicans to try to repeal the new law. The House of Representatives put the finishing touches on the overhaul by passing a companion package that would make insurance more affordable, raise taxes on the wealthy and close a gap for prescription drug coverage for seniors. The Senate approved the package earlier in the day. It now goes to Obama to sign. The votes concluded a yearlong political struggle that tied up lawmakers, dented Obama's popularity and set the stage for a bitter campaign for control of Congress in November. “This has been a legislative fight that will be in the record books,” Democratic Senate leader Harry Reid said. Obama, launching a public relations blitz to sell the new program, mocked his Republican critics and said their promise to make repeal of the law the centerpiece of the congressional campaign would backfire. “If they want to have that fight, I welcome that fight,” Obama said in Iowa City, Iowa, in his first major speech since signing the law Tuesday. “I don't believe the American people are going to put the insurance industry back in the driver's seat. We've been there already and we're not going back,” he said. The overhaul of the $2.5 trillion health care system is the most dramatic change in health policy in four decades. It will extend coverage to an estimated 32 million uninsured Americans and bar insurance practices like refusing coverage to those with pre-existing medical conditions. The final changes approved by Congress on Thursday include an expansion of federal subsidies to make insurance more affordable and more state aid for the Medicaid program for the poor. They also eliminate a controversial Senate deal exempting Nebraska from paying for Medicaid expansion costs, close a gap in prescription drug coverage for seniors and delay a tax on high-cost insurance plans. The final package also would extend taxes for Medicare, the federal health insurance program for the elderly, to unearned income. It also includes reform of the student loan program. Republicans have fought the measure as a costly government takeover of healthcare that would restrict patient choice and drive up insurance premiums.