Democratic spin doctors have set out how their side is going to hold onto a majority in the House. They'll capture four at-risk Republican seats, hold half of the next 30 or so Democratic at-risk seats, and avoid significant losses on target seats lower on the list.
That's one plausible scenario. The shift of opinion away from Democrats so evident in the polls could turn out to be illusory. The widely held assumption that Republicans will turn out in greater numbers than Democrats could prove wrong.
Democratic candidates do indeed have a money advantage in many close races, and their campaign committee has more cash than its Republican counterpart.
All that said, this Democratic spin sounds a lot like the Republican spin back in the 2006 cycle. If the numbers don't change too much from 2004, Republicans said then, we can hold on. If the numbers don't change too much from 2008, Democrats think now, they can hold on.
But the Republicans, as George W. Bush said, took "a thumping" in 2006. And most signs suggest Democrats will take a thumping this year, too.
To see why, take a look at the generic ballot question: Which party's candidate will you vote for in elections to the House? The current realclearpolitics.com average shows Republicans ahead by 45 percent to 41 percent. Ten of this month's 15 opinion polls asking the question had Republicans ahead; Democrats led in four (twice by 1 percent), and one poll showed a tie.
Keep in mind that the generic ballot question historically has tended to under-predict Republican performance in off-year elections. Gallup has been asking the question since 1950 and has shown Republicans leading only in two cycles, 1994 and 2002, and then by less than the 7 and 5 points by which they won the popular vote for the House in those years.
So the Republicans' current lead in the generic ballot question suggests they may be on the brink of doing better than in any election since 1946, when they won a 245-188 margin in the House -- larger than any they've held ever since.
Another metric is daunting for Democrats. Polls in House races almost always show incumbents ahead of challengers, because incumbent members of Congress are usually much better known than their opponents. An incumbent running below 50 percent is considered potentially in trouble; an incumbent running behind a challenger is considered in deep doo-doo.
In 1994, I wrote an article in U.S. News & World Report arguing that there was a serious chance that Republicans could capture the 40 seats that they needed then, as now, for a majority in the House. It was the first mainstream media piece suggesting that, and it appeared on the newsstands on July 11.