The Six-Year Itch is a Myth (for the House)

At Mischiefs of Faction, Dave Mayhew questions the idea of a six-year itch in House elections:

Here are the average House seat losses.

• 28 – first midterm (including Truman)
• 29 – second midterm (including Truman)
• 24 – first midterm (without Truman)
• 29 – second midterm (without Truman)

There it is, you might say. Leaving aside Truman, the contrast of 24 versus 29 shows exactly a special six-year itch. But not so fast! All these numbers are small. They can easily be veered. What about Obama? We don’t have a sixth-year result for Obama, but we certainly do have a second-year result—the Democrats lost 63 House seats in 2010. Why lose this information? Plugging it in moves the above first-midterm figure of 24 to a higher 29. As for the second midterm, does anybody expect a Democratic loss of House seats in November 2014 that exceeds 29? Probably not. When the dust settles next November, it is an excellent bet that adding Obama’s two midterms to the comparison will kill off entirely any idea of a special sixth-year penalty on the House side. Also, note that five of the relevant presidents have lost more seats, or in Obama’s case will have done so, in their first midterm than in their second—Wilson, the asterisked Truman, Reagan, Clinton, and Obama. Only three have lost more in their second midterm—FDR, Eisenhower, and Bush 43. How about losing party control of the House? Truman, Eisenhower, Clinton, and Obama suffered that fate in their first midterm. Wilson and Bush 43 suffered it in their second.

He does point out that there is a six-year itch in Senate elections. Senators who win on a president's coattails must run without them under very different conditions six years later. In 1980, the GOP took over the Senate in a great year for the party nationwide.  But 1986 was not so great, and Republicans lost their majority.