Here's something you don't see every day: A Republican candidate for one office and a Democratic candidate for another office standing together at a press conference being held to criticize a Republican incumbent.

That's scheduled to happen today in Santa Clarita, where Democratic congressional candidate Lee Rogers of Simi Valley and Republican Assembly candidate Scott Wilk of Santa Clarita intend to call out Rep. Buck McKeon because of his refusal to back a federal land swap that would eliminate the threat of a sand and gravel mining operation from opening in Soledad Canyon.

The proposed mine is immensely unpopular in Santa Clarita, both because of the dust and noise it would generate and because the company estimates the mine would generate 1,200 truck trips a day on the congested Highway 14 that is the bedroom community's only route to and from Los Angeles.

U.S. Sen. Barbara Boxer has proposed legislation that would allow the mine permit holder, CEMEX, to swap its permit for one on more remote land near Victorville. The company supports the legislation. The city of Santa Clarita supports it. The Chamber of Commerce supports it. The local Sierra Club chapter supports. But Rep. McKeon does not.

The press conference is to call attention to a bill sponsored by McKeon and approved by the House on Tuesday that authorizes the Forest Service to acquire two parcels of land and essentially swap them for some cash and 20 acres now controlled by the Mammoth Mountain ski resort. Rogers and Wilk are expected to assert that such an exchange, sponsored by McKeon, is no different from Boxer's proposed sand and gravel mine exchange, which McKeon has declined to support.

That a Democratic candidate and a Republican candidate would stand together is unusual -- except that, in one sense, both are running against the same opponent. Or at least the family of the same opponent.

Rogers is running against McKeon in the 25th Congressional District. Wilk is running against the congressman's wife, Patricia McKeon, in the 38th Assembly District. Any unfavorable publicity about the McKeons that might be generated by the press conference would help them both.

It's not for nothing that it's sometimes said that politics can make for strange bedfellows.