Why McCain?
On environment, energy policy, campaign finance, tobacco, torture, pork-barrel spending, immigration and more, Senator McCain has repeatedly worked against his party. In 2001 he almost left the Republican party to become an independent. And in 2004, he was almost chosen for Senator John Kerry's VP slot. He voted against the Bush tax cuts, and against a constitutional ban of gay marriage. He has worked with Senator Ted Kennedy creating an immigration bill that the GOP does not support.
McCain and Hillary share very similar views.