The left-leaning watchdog group, which has pressured advertisers to yank support of conservative media personalities, ranks Andrew Breitbart, Sean Hannity, Rush Limbaugh and others in separate "tiers" of influence, beliefs and reach. Now that Media Matters has declared victory over Glenn Beck, what's next on its agenda? Getting Donald Trump to stop questioning where President Obama was born, perhaps, or maybe convincing advertisers to yank their support of another show on Fox News Channel. Maybe the left-leaning watchdog group will step up its campaign against online entrepreneur Andrew Breitbart. Whoever takes Beck's time slot when he ends his Fox News...