San FRANCISCO — A BATTLE is looming over America’s public lands.

It’s difficult to understand why, given decades of consistent, strong support from voters of both parties for protecting land, water and the thousands of jobs and billions of dollars in economic benefits these resources make possible.

Last week, the United States Senate voted 51 to 49 to support an amendment to a nonbinding budget resolution to sell or give away all federal lands other than the national parks and monuments.

If the measure is ever implemented, hundreds of millions of acres of national forests, rangelands, wildlife refuges, wilderness areas and historic sites will revert to the states or local governments or be auctioned off. These lands constitute much of what’s left of the nation’s natural and historical heritage.

This was bad enough. But it followed a 228-to-119 vote in the House of Representatives approving another nonbinding resolution that said “the federal estate is far too large” and voiced support for reducing it and “giving states and localities more control over the resources within their boundaries.” Doing so, the resolution added, “will lead to increased resource production and allow states and localities to take advantage of the benefits of increased economic activity.”