As some insurers angle for hefty premium hikes and concerns grow that more Americans will wind up uninsured, the federal health law is likely — once again — to play big in both parties' strategies for the contentious 2018 election.

Meanwhile, the impact of changes to the law made by Republicans over the past year is becoming clear. Initial announcements show health insurers in several states are seeking big increases in premiums for next year for people who buy their own insurance. That is renewing concerns about the potential for "bare" counties that will have no insurer selling coverage and hints that the number of uninsured Americans could again be on the rise.

"It's sort of Insurance 101," said Sabrina Corlette, a research professor at Georgetown University's Health Policy Institute. Insurers "are facing a smaller and sicker risk pool as a result of both Trump administration and congressional action, and that means higher premiums."

Among those changes are the elimination of the tax penalty for those who forgo insurance, included in December's tax overhaul, and President Donald Trump's cancellation of federal payments to insurers who provide discounts to some low-income customers.

The heightened political rhetoric over who is to blame comes after the first two states unveiled insurance company premium requests for policies on the individual market for 2019.

In Virginia and Maryland, insurers are seeking a wide range of significant increases, from about 15 percent for some plans up to more than 91 percent for one Maryland PPO.

Analysts are not surprised by the requested rate hikes and predict more to come. The first requests in past years have often moderated before being finalized, but this year's political uncertainties could play a bigger role.

Chet Burrell, CEO of CareFirst Blue Cross Blue Shield, which serves both Maryland and Virginia markets, told the Washington Post that "continuing actions on the part of the administration to systematically undermine the market … make it almost impossible to carry out the mission."

Other insurance groups, though, caution it's early in the process and many things could change. Maryland, for example, has passed legislation to create a "reinsurance" pool that could substantially lower premiums for next year. It still requires formal permission from the Trump administration, however.

Rovner writes for Kaiser Health News.