President Obama has his work cut out for him. Stocks plunged on Wednesday, the first day of trading after Obama’s reelection. The Dow Jones Industrial Average was down 2.3 percent, or more than 300 points. The benchmark Dow was trading below 13,000, its lowest level since Aug. 3. Investors are likely reacting to Mitt Romney’s loss and the looming “fiscal cliff,” with one expert saying that the “chances of going off the cliff probably just increased.” One former Obama administration adviser has put the odds at zero that the president and Congress will have a meaningful compromise by the year’s end.