Slate's John Dickerson agitates, "Run, Elizabeth, Run!"
If Warren joined the race, she would not win, but she would till the ground, putting grit and the smell of earth in the contest. She would energize the Democratic Party’s liberal base, which would then stir up other Democrats who seek to moderate or contain that group. Warren would challenge the Democratic Party on issues like corporate power, income inequality, and entitlements. She would be a long shot and she would have nothing to lose--which means she could keep talking about those ideas out loud. Because Clinton is close to Wall Street and finance executives and Warren is gunning for them, she has the potential to put campaign pressure on Clinton that other candidates can’t. Clinton and other candidates would be forced to explain where they stood more than if Warren weren’t in the race.
I question the proposition that anyone could ever compel Hillary Clinton to explain precisely where she stands on anything (except of course her undying support for Israel). She's a perfectly constructed machine of political ambiguity, which explains her vast popularity and means, as Dickerson also notes, her presidential campaign "will have all the safety, risk aversion, and lack of impact of Clinton’s recent book, Hard Choices." But what the hell. A Warren stab at the alarmingly impossible would possess an incalculable entertainment factor, which would be something, at least, in the otherwise alarmingly dull, Great Coronation run-up.