The polls have been looking pretty good for John McCain in recent weeks, but now there's word his support is softening among a key constituency: His in-laws.

Cindy McCain's half sister, Kathleen Hensley Portalski, told Us magazine she's voting for Obama. "I think his proposals to improve the country are more positive and I'm not a big war believer," Portalski said.

Portalski, 65, and Cindy McCain, 54, are not exactly chummy. Portalski told Us that Cindy is cool and standoffish. She was also sore that McCain was featured in an NPR story earlier this month as an "only child." Portalski and McCain share the same father, Jim Hensley, the founder of beer distributor Hensley and Co., which is the source of much of Cindy McCain's wealth. Interestingly, according to NPR, while Hensley provided financial support to Portalski and her children over the years, he willed his entire estate to Cindy. Portalski was left with $10,000.

For someone from the party of "family values," McCain's sure having trouble rounding up the votes of his relatives. Us also reports that Portalski's son, Nathan, plans to back Obama as well. Nathan had some harsh words for both McCains.

"I wouldn't vote for John McCain if he was a Democrat," he said. "I would not vote at all before I'd vote for him." He went on: "I question whether Cindy is someone I'd want to see in the White House as first lady."