Trump’s Rollback of Auto Pollution Rules Shows Signs of Disarray

The White House, blindsided by a pact between California and four automakers to oppose President Trump’s auto emissions rollbacks, has mounted an effort to prevent any more from joining the other side.

Toyota, Fiat Chrysler and General Motors were all summoned by a senior Trump adviser to a White House meeting last month where he pressed them to stand by the president’s own initiative, according to four people familiar with the talks.

But even as the White House was working to do this, it was losing ground. Yet another company,...