- The last time the Republicans won control of the Senate was 8 years ago when George W. Bush was President. Two years later Barack Obama was elected President and the Democrats retook control of the Senate not long after George Bush's approval rating hit an all-time low (19%).
- Toward the end of President Bill Clinton's second year in office, when his approval rating got as low as 38% (not the lowest but close), Republicans gained control of both houses of Congress, and most people believed Clinton would be booted out of office when he came up for reelection. That, of course, is not what happened. The next two years were among Clinton's most successful, he was easily reelected, and he left office with relatively high approval ratings.
Moreover, voter demographics continue to favor Democrats for national elections. In nonpresidential election years, minorities and young people are more likely than are older, white voters to stay home and not vote, meaning that conservative voters make up a disproportionate share of the electorate. That is unlikely to be the case two years from now when there's a strong possibility that Hillary Clinton will be the Democrat nominee ("How Hillary Clinton won the 2014 midterms"):
It’s one thing to win an election in a nonpresidential year, when minorities and young people stay home and older, whiter voters make up a disproportionate share of the electorate. It’s another thing to win when a Democratic presidential candidate is luring the party’s base back to the polls — especially when that candidate is Hillary Clinton, the most popular Democrat in America.
To be sure, a lot can and will happen between now and 2016, and I'm not quite ready to trot out my quadrennial presidential election predictions. I'll wait at least a year before I do that. Still, I don't think the Democrats have reason to panic, at least not yet, and as an editorial in Forbes magazine points out, the Republicans should not be too overconfident ("Republicans humiliated Obama, now they need to humble themselves").