Republicans highlighted a healthcare problem Tuesday that lately has been causing their Democratic colleagues to squirm: Obamacare's insurance costs.

At a House Ways and Means Committee hearing, the GOP members re-aired their favorite complaints about President Obama's healthcare law, arguing that its new requirements on insurers are leading to more costly premiums for consumers.

"The truth about this law is that it has never expanded access to affordable, high-quality health care of an individual's choosing, and it never will," said committee Chairman Kevin Brady, R-Texas.

Insurance premiums were growing faster than inflation for years before the 2010 Affordable Care Act was passed. But it's not clear that the law has put any curb on that, and after insurers proposed hefty double-digit increases for next year, Republicans are arguing that the law has caused costs to grow even faster.

Aggravating the problem is the end of a federal reinsurance program, which transferred money from plans with lower-cost customers to those with higher-cost customers to help insurers during the transition. The phasing-out of that program is thought to contribute to potentially higher rates in 2017.

Democrats pushed back, speaking about more successful parts of the law such as its coverage expansion and saying Republicans are just trying to score political points in an election year.

"You should understand the hearing today is part of the political debate of this year," said top Democrat Sander Levin of Michigan.

"At first I wondered why we are doing this, but then I realized the conventions are next week," said Rep. Charlie Rangel, D-N.Y., referring to the Republican National Convention in Cleveland. "I assume this is to sharpen up our skills for the convention."

Americans have been about equally divided over the law ever since it was passed six years ago, with public opinion only slightly fluctuating. Republicans have vowed to repeal the law every election since, but they say now there's more evidence than ever before that it's not accomplishing its purposes.

"I know it's popular to claim we're fighting for political purposes," Brady said. "In our view, we're fighting for patients."

The Obama administration has said about 20 million Americans have gained coverage because of the law. But it has had to fight criticisms that plans offered on the marketplaces cost too much and severely limit which doctors patients can see.