I think Christians should be informed. I believe they should NOT be informed by the mainstream media. How can you vote intelligently listening to only one side of the story? Everyone has an agenda - especially the media and politicians.
Watch Hal Lindsey. He's on TBS, Daystar, and online. He has a great report and it is usually news and commentary from the standpoint of the Bible, though I do not agree fully with his scenario of the End Times.
Some Christians are called to be political leaders; otherwise where would America be without the strongly Christian founding fathers?
Do not believe the lie that they were deists - read their quotes - as far from deism as you can get.
And yes, even political leaders should practice the Great Commission.
And we should pray for them. Not that their ungodly agendas succeed, but that they may grow in the knowledge and practice of Truth.