GOOD MORNING: Robert Downey Jr.’s arrest Saturday night at Merv Griffin’s hotel and Givenchy Spa in Palm Springs has cast a pall over this community … A major Hollywood player who had also been addicted, told me how difficult it is to break that horrible habit. “I tried for four years — and finally did,” he admitted. Merv Griffin’s comment — “It’s so sad!” — expressed the reaction of almost all to whom I spoke Monday. The damage to Downey’s career is, of course, obvious, but what about his life? Griffin said, “We should form a group of fellow actors — first of all to keep him from going to prison — what good would that do? And then, to give him the medical help he obviously needs.” Griffin who has a (breathtaking) ranch at La Quinta, visited his hotel Saturday afternoon for lunch. “And I hoped I might meet him. I had admired his work since ‘Chaplin’ — what a remarkable performance. And I’ve been watching ‘Ally McBeal’; he’s given that series such a lift!” … Sara Gilbert was also at Griffin’s hotel over the weekend and told Merv she had hoped to catch a glimpse of Downey when she learned he was there. Neither Gilbert nor Griffin caught sight of Downey, who remained most of the time in his room (once with a “blonde” lady). Gilbert had winged in from New York where she’s co-starring in the CBSeries “Welcome to N.Y.” and where she’d completed the feature “Riding in Cars With Boys” with Drew Barrymore and directed by Penny Marshall. Gilbert was in L.A. Monday to join family members, sister Melissa Gilbert and mother Barbara (Mrs. Warren) Cowan, for the unveiling of the tombstone of grandfather Harry Crane at Mt. Sinai … On a more pleasant note for Griffin, on Sunday, his horse, The Griff was a winner in a maiden allowance race at HollyPark. It paid $6.20 to win, purse $39,000 — plus Merv’s considerable winning tix.LIBERAL AND REACTIONARY POLITIX — and monkey bizness: The Senate, in Tim Burton’s “Planet of the Apes” produced by Richard Zanuck now boasts the addition of David Warner — to play an esteemed liberal member of the apes’ Senate and father of Helena Bonham Carter. They sympathize with the plight of the oppressed humans — two of whom are Mark Wahlberg and Estella Warren. On the other side of the Senate aisle is Tim Roth, the ape leader who considers humans as animals, as does Michael Clarke Duncan. Warner reminds that this is not the first time he has gone ape. In 1966 he starred in the title role of “Morgan — A Suitable Case for Treatment” and in the final scene he donned a gorilla suit to disrupt his ex-wife’s wedding. Warner has high praise for Rick Baker’s extraordinary “Planet of the Apes” makeup — even if he has to report at 3 a.m. Helena Bonham Carter’s makeup call is 2:30 a.m. That’s really showbiz! … Now about Arnold Schwarzenegger running for governor of California “when the time is right,” according to the London Times: Arnold, from Mexico and filming “Collateral Damage” in L.A., laughed. “IF I EVER decide to run, you will be the first to know” … When then-actor, pre-governor Ronald Reagan was serving in the First Motion Picture unit, he assigned Richard Gully to share an office with writer Mal Wald. Gully’s first assignment was a highly secret project about the planned Allied invasion of Sicily and the project involved Gully, Wald, Reagan and several RAF pilots. Wald is now writing a play about this fascinating, untold war story. A SOLUTION FOR FUTURE presidential elections from Pat Boone: first, scrap the Electoral College; second, have a Democrat serve four years, then a Republican. Then have the public vote on what to pay them … Lauren Bacall returned to N.Y. Monday night, after having been a guest in Milan at Paolo Liminti’s Ci Vediama Su Raal 1, which paid tribute to her over three days’ airing. She then was part of the tribute to Leonard Bernstein in Paris where Marlon Brando was supposed to join Bacall in the tribute — but did not. Next, Bacall winged to Stockholm as this year’s recipient of the Bronze Horse, Scandinavia’s most prestigious film award. She now has mini and full series offers awaiting her decision … The late Loretta Young will be honored at the second annual Bishop Gerald R. Barnes Dinner March 10 at the Air Museum in Palm Springs. Funds raised ($2.5 million is hoped for) will be used to build the Sarra Home to house and educate seminarians … Candice Bergen, Gregory Peck and Jennifer Jones Simon will host guests at the world premiere of “The Art of Norton Simon,” the 30-minute docu directed by Davis Guggenheim, produced by Charles Guggenheim at the inauguration of the newly renovated Norton Simon Museum Theater. The galleries, recently renovated by Frank Gehry, will be open to guests … Constance Towers sings at the Colorado Springs World Arena Dec. 17, along with the U.S. Air Force Band of the Rockies … Added glitter to Denise Rich’s G&P Foundation Angel Ball for cancer research, Nov. 30, at the Marriot Marquis: Chopard jewelers will place a one-carat diamond (value $7,000) in a box of Chopard chocolates given to one of the lucky guests … KOCE-TV and Classic Digital are looking for participants to fund a one-hour tribute to classic songs by composers including Stephen Foster, Victor Herbert, Irving Berlin, George Gershwin, Aaron Copland and Richard Rodgers.