I should add: while I do think that it's reasonable to give Cheney a platform to express Republican views of the president, I think the critics are correct in their comments about the Politico story as journalism.
It certainly would be nice to know how Cheney, who apparently thinks that Afghanistan was going well until Obama took office, would respond to a question about why the military thought that a significant increase of troops there was necessary after Obama already increased troop levels this year. Does Cheney believe troop levels were correct for the seven years that the Bush/Cheney administration ran that war? If he thinks (as he apparently does) that more troops are needed now -- more quickly than Obama is sending them! -- what does he think changed between January 19, 2009 and January 20, 2009 that suddenly required lots of new soldiers on the ground? At the very least, Allen and Vandehei might have provided a bit of the factual background.
Republicans deserve to be heard, and they're entitled to Cheney if they want him, but they aren't entitled to presenting their views without fear of tough questions.