Congress' consistently lousy poll numbers (13 percent approved at the beginning of the month) are often explained away with, "Yes, but people like their own representatives." That's never been less true.

According to Gallup, a record low number of people want to keep their current representation in Congress, dipping below the 50 percent mark for the first time since the early 1990s. In the graph below, the dark green line shows the number of people who think their own members of Congress deserve reelection — a number that plummeted between late 2012 and now.

The light yellow line in that graph, by the way, shows the extent to which people feel as though Congress in general should be ousted. (Or, rather, the extent to which they feel most of Congress should be kept.) Not only is it a record low, with only 17 percent of Americans thinking that most members of Congress deserve reelection, but it's the lowest number by a healthy margin — a 19-point drop since November 2012.

Gallup points out that this often correlates with turnover at the polls — although the data only goes back to 1992 and there haven't been that many elections in which to test the hypothesis. The graph below contrasts the percentage of Americans who didn't say they wanted to keep most of Congress (the blue line) with the actual net turnover in seats the following election. Generally — but only loosely correlated — the higher that blue line of people who wanted to dump politicians, the more politicians that got dumped.

You'll notice that 2012 is something of an exception, with a lot of people not saying they wanted to keep most of Congress, but only a few people ousted. That tracks with the uptick in approval in that November 2012 poll, an election cycle in which a lot of people paid a lot of attention to politics and a record amount of money was spent by President Obama and Mitt Romney to try and convince people of their merits. It seems logical that people would feel more antipathy about their elected officials when those elected officials aren't actively running ads saying how great they are.

So the question is: Will this January number mean a lot of incumbent losses in November? We'll see. But those incumbents have an awful lot of money to remind their voters why they are so great for the community and how much they love America and so on. The volatility of those two green lines in recent years can be seen as much a reason for optimism on Capitol Hill as anything.