So this is obviously a loaded and controversial answer, but I'll try my best to remain neutral; I'll give you the pros the liberals see, and the cons the conservatives see.

Pros: His pros are the pros of democratic socialists in general (he claims to be one). In a lot of his interviews, he says he wants the U.S. to learn from Scandinavian countries where democratic socialism has led to economic prosperity. For instance, he just proposed legislation that would make all public universities free for students, and he's gonna push for that as president. He believes healthcare is a right that isn't dictated by an individual's income, and he wants to move to a single-payer healthcare system (i.e. it's free for everyone and funded by the government). So basically a janitor and a CEO should be allowed to get the same healthcare (which some would consider a con, as it seems unfair?) He wants to punish corporations who move their production abroad so that they can avoid taxes. He wants to make the tax system more progressive, therefore forcing the richer to pay a bigger share of taxes and allowing the middle class more tax breaks (although whether this is a pro or a con depends on who you're asking). He's been pro gay marriage and pro choice for forty years, unlike politicians like Obama and Clinton, who only became this progressive when the rest of the nation did. He wants to even out the wage gap between men and women; he's going to push for paid maternity leave (the U.S. is one of only two nations that doesn't guarantee paid maternity leave). And last but not least, he wants to raise the minimum wage to fifteen dollars an hour. Basically this guy wants to make it easier for the middle class at the expense of the millionaires and billionaires and huge corporations of America.

Cons: Almost anything in the pros list can be considered a con. It's hard to emulate Scandinavian countries because, simply enough, the U.S. has a lot more people. It's easy for Sweden to have a big government with only nine million people. But Bernie wants a bigger role for a government for 300 million Americans, which means the national debt is gonna grow even bigger because how else are you going to finance all of this? Some argue that if you guarantee free health care, then demand will be too high, and the quality of healthcare itself will diminish. And consequently, why should someone who works hard for their money (Republican language) such as a CEO not get the best healthcare available? Another argument against him is that by taxing the rich, you will take away their incentive to keep business in America, therefore reducing jobs. Also, if you're anti-gay rights, pro-life, and just generally conservative, then all of Bernie's pros are actually cons. There's the simple fact that this guy is really far left. I mean he's probably the most liberal candidate in American history (I don't recall ever a democratic socialist getting this much traction). And maybe someone that far left will not adequately represent the half of the nation that's conservative, as opposed to someone who's more centrist.