TRUST Mitt Romney to be on top of the latest trend of the superrich: the trophy basement.

On Friday, The Wall Street Journal reported on the new fashion to look low-key on the outside while digging deep for opulence — carving out subterranean spaces for Turkish baths, Italianate spas, movie theaters, skateboarding ramps, squash courts, discos and golf-simulation centers.

The Journal reported that Romney has filed an application to replace his single-story 3,000-square-foot beach house in La Jolla, Calif., with a 7,400-square-foot home featuring an additional 3,600 square feet of finished underground space.

It’s a metaphor alert, reinforcing the two image problems Romney has: that he’s an out-of-touch plutocrat and that his true nature is buried where we can’t see it.

His two-year missionary stint in France taught Mitt to steel himself against rejection. Still, he must feel awful heading into Illinois (where Joseph Smith, the Mormon Church founder, was running for president when he was killed by a mob), spending so much money to buy so little affection.