Hillary Clinton is theoretically a highly vulnerable candidate. She has been “caught” — in plain sight — being a Clinton, meaning her abnormal attachment to money has driven her into the pockets of big donors who seem like a Who’s Who of Evil Forces in a MoveOn.org ad. Dick Cheney played small ball, merely working for Halliburton before running for VP (by which time he had ended his relationship). Clinton goes right into the heart of oil kingdoms, Goldman Sachs and chemical and drug companies to support her foundation, which has as a key function the luxury travel of the Clintons and their retinue. She has no discernible policy proposal on much of anything. Her political skills cannot be called “rusty,” for they were never lustrous. She served as the president’s top foreign policy official, making her the co-author of a foreign policy distinguished by its ineffectiveness and lack of principle, unless one considers allowing evil forces to run amok to be a principle. In sum, she is viewed with disdain by the base and extremely vulnerable in a general election. In many respects (her political awkwardness, lack of ideological authenticity, age), she has morphed into Mitt Romney (minus his superhuman generosity).

DES MOINES, IA - OCTOBER 19: U.S. Sen. Elizabeth Warren (D-MA) campaigns for U.S. Rep. Bruce Braley (D-IA) on October 19, 2014 in Des Moines, Iowa. Braley is in a tight race for a Senate seat against Republican challenger Joni Ernst. (Photo by Steve Pope/Getty Images) Sen. Elizabeth Warren (D-Mass.) campaigns for Rep. Bruce Braley (D-Iowa) last year in Des Moines. (Steve Pope/Getty Images)

So, why does Sen. Elizabeth Warren (D-Mass.) not roll the dice? All it would take to break the illusion of inevitability is a strong run in Iowa, not even a win, but a close second to the Clinton machine. Iowa was Clinton’s downfall in 2008 when a newcomer ran to her left. Ideal for a left-wing challenger, Iowa is small enough for an underdog with a cult following to capture. Advertising is cheap, and free media are plentiful.

Warren would alleviate a host of problems for the Democrats. The 2016 race would no longer be an election about President Obama’s failed foreign policy, nor would she have to take ownership of Obamacare’s problems. Single-payer healthcare reform! Carbon taxes! The laundry list of unfulfilled liberal dreams would have a fervent advocate.

Frankly, even a modestly ambitious pol would see the opportunity here. Even if Warren runs and loses, her stock with the left may go up. So is it just abject fear of the Clintons that is keeping Warren back? Certainly, Democratic insiders and donors won’t want to cross Bill and Hillary. Every elected official will be strong-armed to stick with Hillary Clinton. But that was true in 2008 as well — until Obama began to win. And the plethora of independent left-leaning donors with no loyalty to the Clintons means there will be plenty of money swirling around.

Republicans frankly don’t have a game plan for running against anyone but Hillary Clinton. With her the campaign themes write themselves. Run against a third term. The future vs. the past. Outsiders vs. the Beltway. For Republicans it is always harder — as we saw in 2008 and 1992 — to run against an inspirational newcomer than against an insider and tired defender of the welfare state (Michael Dukakis, Walter Mondale). And for Jeb Bush (who can rely on her dynasty to cancel his), the prospect of a fresher face would raise new challengers.

But none of that happens if Warren does not give it a shot. Given Clinton’s obvious and growing list of shortcomings, Republicans remain amazed and relieved that she seems disinclined to do so.