Massachusetts Senator Elizabeth Warren and Vermont Senator Bernie Sanders are increasingly seen as leaders of the progressive wing of the Democratic Party, largely as a result of being the most talked-about alternatives among progressives to Hillary Clinton as the 2016 Democratic presidential nominee.
Progressives who are most enthusiastic about Warren and Sanders tend to be those most engaged on the issues of challenging Wall Street and corporate power and making the economy work for the majority of working families. It's obvious why those issues are at the top of the marquee as people fight about 2016.
But if you're going to be an alternative to Hillary, you have to be an alternative to Hillary all the way around, not just on corporate power and the economy. That doesn't mean, of course, that you have to have the most progressive position on any issue that anyone can imagine -- that's obviously not how it goes. But if most Democrats have a progressive position on an issue, you should not be far away from majority Democratic opinion.