To understand the weakness of Hillary Clinton's position, you need to understand her appeal as a candidate. She has no identifiable political legacy, no issue or set of positions that mark her ground. Instead, she is a symbol, as Ross Douthat put it last week, which seeks to unite the Democratic working-class (her base in 2008) with the identity-politics impulses that drive the core Obama voters. She is, in that way, a continuation of the Obama appeal, but without any of the political or policy baggage from the Obama administration. In fact, she's one of the few Democrats who can run without any firm attachment to Obama's tri-partite political legacy of Obamacare, high unemployment, and a stagnant economy. Clinton can be Obama's heir, but it's hard to pin any of those problems on her.
The only part of Obama's legacy that will stick to Clinton is his foreign policy.
For four years, that seemed like a great arrangement. But suddenly, over the last year, it's begun to look quite perilous. Obama_perhaps you've heard this?_got bin Laden. But other than that, his foreign policy record is disastrous: Libya, Egypt, Syria, the South China Sea, Crimea, Iraq, Afghanistan. It is difficult to find a spot on the globe that is better off today than when Obama took office. And yet Obama's foreign policy is the only entry of substance on Hillary Clinton's resume right now. Which means it will carry double the weight.
For Obama, Putin and Crimea are a mid-size political problem, ranked somewhere above the Keystone pipeline. For Clinton it's an existential problem because foreign affairs are the only measures for her basic professional competence.
Think about it from the perspective of a Democratic voter: Hillary Clinton was wrong on Monica Lewinsky during the (Bill) Clinton years, wrong on gay marriage and Iraq during the Bush years, and now wrong on Putin and Syria and Egypt and the whole of American foreign policy during the Obama years. What has she ever been right on? And if you're a Democratic voter, at some point you start to wonder, Can't we do better?