Like so many great romances in history, the affair between Franklin Delano Roosevelt and his cousin began with a timid hand job. At least, that's how his paramour Daisy (Laura Linney) remembers it. In Hyde Park on Hudson, director Roger Michell raids the late Margaret "Daisy" Suckley's journals to bring us the tale of her naughty exploits with distant relative FDR (Bill Murray), who woos her first with his great big stamp collection, and next with his sweet off-roading skills. The president thrills Daisy with wild rides through the woods near his mother's upstate New York mansion, where he's come in 1939 to get his mind off an impending world war. On one fateful jaunt, he squires Daisy into a clearing filled with wildflowers and, right there in his Ford convertible, invites her into the presidential pants for the first of many clandestine sexual favors. Ah, incest.

Leave it to Murray, though, to make something as icky as incest seem somehow sweet and forgivable. He's an enchanting FDR, aglow with twinkle-eyed mischief and Poughkeepsian "huh-what's" and "huh-why's." Murray musters the potent charisma that supposedly enabled the 32nd president to sustain multiple affairs simultaneously, and he grins his way through incessant white-gloved catfights between his mistresses, wife and mother. His gaggle of doting ladies are well cast, three in particular: Linney's skittish Daisy darts about with irritating but convincing anxiety; Olivia Williams becomes a bold and pragmatic Eleanor Roosevelt; and FDR's mother (Elizabeth Wilson) is deliciously bitchy.

Then into the covetous hubbub waltz the King and Queen of England, on their first visit to America, hoping to convince President Roosevelt to back them in World War II. King Bertie (Samuel West) and Queen Elizabeth (Olivia Colman) are amusing as they shuffle languidly through dinner parties and photo ops, aghast at such crude American traditions as hot dogs and political satire. With the help of rosy quips and a slew of martinis, FDR gets the prudish Brits to loosen up, making his way to the moral of this film: Whether you're a king with a stutter, a lady with the hots for her cousin or a president in a wheelchair, the key is finding happiness in what is, rather than in what should be. Whatever helps you sleep at night, Mr. President.

Critic's Grade: B+

SEE IT: Hyde Park on Hudson is rated R. It opens Friday at Fox Tower.