Paul Waldman has an interesting post up at The American Prospect, “Why Hillary Clinton Could Be the Kind of President Bernie Sanders Supporters Will Love.” As Waldman frames his argument:

It’s frustrating to be a Bernie Sanders supporter right now. Your candidate has plenty of impressive wins behind him, Hillary Clinton is still far from having the nomination wrapped up, and yet everyone is talking as if the race is over. First they didn’t take your guy seriously, and now they want to push him out of the race. With the expectedly raucous New York primary coming up Tuesday, it’s no wonder that there’s no small amount of animosity coming from Sanders fans toward Clinton. In fact, in a recent McClatchy/Marist poll, 25 percent of Sanders supporters say they won’t vote for Clinton if she’s the party’s nominee.
They may not want to hear it yet, but those who support Sanders might start thinking about how they could exert influence over Clinton’s presidency. Because some of what they don’t like about Clinton–her caution, her propensity for difference-splitting, her inclination to seek the path of least resistance–is exactly what will enable liberals to pull her to the left once she’s in the White House.

Waldman notes that Clinton’s earlier “centrism” was partly anchored to the prevailing trend of her party in the 1990s. “Who she was then,” says Waldman, “was a combination of her natural inclinations and a keen eye for the political risks and possibilities of the moment. On that basic level, she hasn’t changed, but the environment has.”
But now, adds Waldman,

The Democratic Party has moved to the left on many issues, from gay rights to immigration. At a time when the parties and their voters are polarized, and Democrats have significant demographic advantages at the national level, there’s little to be gained by moving to the center. So Hillary Clinton is a much more liberal politician than she was twenty years ago.

It is a mistake for progressive Democrats to assume that Clinton is an ideological centrist. One can make a case that she was always a notch or two to the left of her husband, but those instincts were reigned in, rightly or wrongly, by pragmatic caution.
However, says Waldman, “If liberals can move the country’s debate and the Democratic Party’s fulcrum to the left, then Clinton will move with them.” For Sanders campaign supporters, “that means that when the Sanders campaign is over, their work will just be starting. As president, Hillary Clinton will be as liberal as liberals force her to be. If they do their job, that could be quite liberal indeed.”