Yes, I see much passionate support for Bernie Sanders, especially online. Perhaps Hillary Clinton also has passionate supporters, but the supporters for Bernie Sanders seem more visible. I see posts on social media in support of Bernie Sanders almost every day. I have seen far less support for Hillary Clinton on social media.
The supporters of Bernie Sanders show their passion for his campaign more than Hillary's through their incredible fund raising efforts, outstanding support on social media, and rallies which tend to overflow with people who are ready for the change Bernie has been promising. While Hillary does have a solid group of supporters, Bernie's tend to be more outspoken about their passion for his presidency. Bernie's campaign has already been more successful than many of his supporters were expecting, and their momentum continues to grow with each state he wins. This gives Bernie the role of the underdog in the Democratic campaign, and those who are rooting for him are rooting for him loudly and passionately.
One of the greatest issues for Democrats is low voter turnout, and I'm not sure there's been any "frontrunner" less inspiring than Hillary. All of her supporters have a tone of "lets get this over with" that only serves to let Trump win the general election. It would be a lot easier for Sanders to earn former Hillary supporters than Hillary to suddenly become invigorating and motivating. "I'm not him" isn't good enough.
Both Bernie Sanders and Hillary Clinton have a vast number of supporters. They are vocal, and passionate, and are devoted to their candidate. While Bernie Sanders' followers are more visible and loud in voicing their support, I'm sure each candidate (including Hillary Clinton) has their own group of loyal supporters. Unfortunately, so does Donald Trump. Beware!