Even granting that such things aren't necessarily the best gauge of the health of the broader economy, that the markets don't seem to like this whole re-election business could be very problematic for the President. If the current trend continues, it could be as much a leading indicator of tough times to come as it is a laggard indicating displeasure.
While many will find it difficult to empathize with the 'Wall St. crowd' in the abstract, it is also true that many regular people have 401ks, pensions, and other retirement and savings accounts which are heavily invested in equities. The better those accounts perform, the more confident people will be in the economy and the direction of the country; the more confident they are in those things, the more likely they will be to accept things like tax code and immigration reform - two probable hot topics over the next four years.
In short, the more solid the stock market, the easier it will be for President Obama to pursue an aggressive agenda during his second term. Obama may be no friend of Wall St., but you can rest assured that he and his advisors are watching the markets; tough times there could make his second term even more difficult than the first.