I finally did my homework. I combed the web pages of Obama and Clinton on the issues last night and this morning. I read lots of blogs and articles comparing the two. When it comes to issues, I have read about 100+ pages more about what each of them stand for than I had until now, covering a fairly comprehensive range of issues. I'm not an expert, but I can now consider myself an informed voter when it comes to the issues in this race.
The conclusion I came to, which is widely shared in the media and the blogs, is that the policy differences between the two are minor. Their substantive agendas are close enough that only someone with a very intense niche interest in the particulars of how a policy agenda is implemented would have any reason to vote differently on that basis. There are issues that one talks about while the other does not, but given the whole of the record, it is clear that both of them share a wide consensus of a host of issues to a significant level of specificity forged in the furnance of the Democratic Caucus of the United States Senate.
Some of the biggest differences that I noted, and a NY Times article notes this as well, is that Obama has a greater focus in how his proposals are structured on simplicity and on behavioral economics (i.e. the impact of default options and how issues are framed on the economic decisions that people make). Clinton, in contrast, often proposals approaches that have a similar effect but tend to make one's eyes glaze over just a little.
Obama communicates his agenda better. He does a better job of capturing the values he is advancing with a proposal even when it is in a quite technical area of the law. This isn't entirely immaterial. Hillary Clinton's best known policy agenda, the health care plan she worked on while Bill Clinton was President, failed to a great extent because the public saw it as too confusing and because what it did was poorly communicated.
The differences in their voting records are likewise minor, and a good share of them reflect situations where one voted against a bill in a tactical effort to secure a stronger one.
Also, while there are very few outright contradictions, Obama does attach greater importance to improving the fairness and efficency of the economy by tweaking problems with the bankruptcy code.
Bottom line. The way to decide this race is not upon substantive policy issues.