WASHINGTON (AP) — A conservative federal judge in Texas on Friday ruled the Affordable Care Act "invalid" on the eve of the sign-up deadline for next year. But with appeals certain, even the Trump White House said the law will remain in place for now.

In a 55-page opinion, U.S. District Judge Reed O'Connor ruled that last year's tax cut bill knocked the constitutional foundation from under "Obamacare" by eliminating a penalty for not having coverage. The rest of the law cannot be separated from that provision and is therefore invalid, he wrote.

Supporters of the law immediately said they would...