Mainstream media biased against 'flailing' Romney? Four points to consider.

Many supporters of Mitt Romney argue that his potential path toward the White House has been made a lot steeper by the media, which have piled on about the Republican's alleged gaffes and policy flaws. Is that perception true? Is media bias against Romney rampant, while the press scrutinizes President Barack Obama through a less skeptical lens?

With a high-stakes election drawing near, here are some of the main arguments pro and con.

• How the news business works
• Who's doing the reporting and editing?
• Public opinion polls
• Is there empirical evidence?