It's lonely these days for members of Bill Clinton's cabinet. Nobody wants their campaign advice, and they weren't invited to address the convention either. So they endured the ennui of Chicago by holding forth over breakfast or lunch with reporters. Interior secretary Bruce Babbitt allowed as how he'd be very, very interested in being nominated to the Supreme Court in a second Clinton term. (Babbitt was passed over when Clinton made Ruth Bader Ginsburg a justice in 1994.) Treasury secretary Robert Rubin made it clear he thinks a cut in individual income tax rates, even a small one, is uncalled for, now or if Clinton is reelected. Wouldn't spur the economy, he said. A rationale that didn't occur to him: letting folks keep more of their own hard-earned money. Commerce secretary Mickey Kantor disclosed the unhappy news that NAFTA has not worked quite as promised. No wonder he doesn't really like being commerce secretary.