If you look at most polls between Bernie and Hillary, Bernie is actually winning.
Some news companies like CNN are actually getting scrutinized for taking down people's pro Bernie comments, and polls on their websites. After the debates CNN took down their own Who won the debate poll, and put up their projection on who is going to win the over all election stats (which where bias), and made it look like a poll's statistics in Hillary's favor.
The reason why (CNN (and many other companies that make more money under the current laws than they would if Bernie got the presidency) do this is because CNN's parent company Time Warner is funding Hillary, who has in the past, helped the companies who have helped fund her campaigns, that is why she has so many big downers, where as Bernie has only accepted small individual donations and isn't indebt to multiple high end companies.
An example of the voters being pro Bernie can actually be seen on this sight, with a poll that I created, is currently Bernie 22 votes to Hillarie's 5, and on one that I didn't do, Hillary had 5 again to Bernie's 45 votes.
I even asked democrats and Independents around me, and have only found one person who is pro Hillary, and the only reason why that was, was because Hillary is female, and had nothing to do with her position on anything.
So yes. I know Hilary is being labelled by the democratic party as the front runner and automatic heir to the democratic presidential nomination but the simple fact is, she is a weak candidate. She gets flustered often and cannot answer the simplest of questions at times and her views on foreign policy are beyond comical. And with the state of global affairs today you cannot afford to be weak on foreign policy, that is the reason Obama's legacy will always be tainted. Ultimately over a long campaign these weaknesses will be highlighted and frequently exploited, especially if she is running against a confrontational character like Donald Trump. A Clinton Bush race would be the most linked to politics and less linked to drama.
I don't think that Bernie Sanders will beat Hillary Clinton, but I think it is good for her to be worried about him. It makes her feel like the primary is more of a competition, and she will be out campaigning more, which will help her during the general election. Also, I think it helps for the public not to think the primary is already a done deal.
Hillary Clinton has been a name in national politics for a long time, and through her history has burned bridges and alienated people in one way or another. Not everyone in the democratic party is ready to support her as a candidate. As well, Bernie has been gaining a following with policies that Hillary has yet to support.
No, Hilary Clinton is running a strong campaign, and she does not have to worry that she will lose favor to Sanders. Sanders is a strong candidate with many years of experience in public service. Clinton was a former first lady with even stronger credentials. Clinton has a strong platform for financial reform, and she addresses many issues such as health care, social reform and law enforcement of importance to Americans. She has remained vague about some issues, yet she could use this strategy to maintain the interest of voters until voting day. Sanders, on the other hand, has been vocal about where he stands on issues. It seems that he has done all he could.
If Hillary Clinton believes in her platform and believes in her constituents enough, she should feel confident about being able to take the democratic nomination. She may win, or she may lose. It ultimately depends on how she takes either position at the end of her run. Clinton has her own strengths that could play out very well in the White House, as does Sanders. Both are qualified candidates and both deserve consideration.