WASHINGTON (AP) — The Trump administration on Thursday announced proposed rule changes that would lead to a modest premium increase next year under the Affordable Care Act, potentially handing Democrats a new presidential-year health care issue.

The roughly 1 percent increase could feed into the Democratic argument that the Trump administration is trying to "sabotage" coverage for millions. The administration said the proposal is intended to improve the accuracy of a complex formula that affects what consumers pay for their premiums.

Premiums under the health law were basically stable this yea...