I have to say I disagree with Charlie Brooker here. What's concerning about the Midsomer Murders casting policy isn't its Caucasian bent, but it's willingness to give the main role to David Cameron from 20 years in the future.
What hideous 2030's disaster has caused everyone's favourite moist-eyed poor-shafter to flee back to our time? Did he irradiate Scotland? Is he haunted by the gladitorial encounter that forced him to choke Nick Clegg to death with a copy of The Big Issue? Or did he run in terror when George Osborne finally revealed his legion of undead Conservative Yourth members and brought eternal night to London?