"It [Obamacare] was the single worst piece of legislation among many pieces of legislation passed in the first two years of the Obama presidency," McConnell said at a press conference in the US Capitol.
Major US health insurance companies have pulled out of the government run exchanges after suffering hundreds of millions of dollars in losses in the previous two years. The law established the exchanges for uninsured people to buy policies from private companies.
When open enrollment for 2017 began one week before Tuesday’s presidential election, many customers discovered rate increases of more than 50 percent.
"Every single Republican [in the US Congress] thought Obamacare was a mistake without exception," McConnell said. "That’s still our view and you can expect us, with a new president who has the same view, to address that issue."
US government subsidies cushion some of the impact, but small business owners and employees are especially hard hit because they earn slightly too much to qualify for government aid, according to critics that include former President Bill Clinton.
Democrats have said they want to fix the existing law. Despite the high cost, Obamacare defenders praise the law for providing insurance to 16 million Americans who had no health insurance.
Republicans, including President-elect Donald Trump, said they want to scrap Obamacare and start over.