The architect Cass Gilbert once said a skyscraper is a machine to make the land pay. It’s hard to imagine a more finely tuned machine than the Trump Presidential Library, a glass-walled Miami tower whose video renderings were released by the president’s son Eric on Monday night. The project has a balance sheet that would make a developer blush. The land side of the ledger is already taken care of: Miami Dade College surreptitiously transferred the Biscayne Boulevard parcel to the state of Florida last year, which then donated it to the president’s library foundation, a giveaway of a waterfront site that one of the college’s former presidents recently called “unimaginable.” The revenue is beginning to take shape as well. The library has already been used to justify the gift of a $400 million presidential jet from Qatar. It has served as the supposed destination for the $63 million in settlement funds (now mysteriously missing) that ABC, X, Meta, and Paramount forked over in response to President Trump’s lawsuits. The president said yesterday that the …