UPDATED HERE.
In 2010 the GOP candidates for the House of Representatives garnered 53.4 percent of the two-party popular vote. As a result, the GOP gained 64 House seats. That showing was echoed in the Senate, where the GOP gained 6 seats.
What’s the prognosis for 2014? It’s 60 days before the election, so it’s too soon to tell for sure. But I’ve concocted some indicators that I’ll update as election day approaches. They’re based on the Obama Approval Index History published at Rasmussen Reports, and Rasmussen’s sporadic polling of likely voters about Obamacare (latest report here).

The first indicator (blue lines) measures Obama’s overall rating with likely voters. The second indicator (black lines) measures Obama’s rating with likely voters who express strong approval or disapproval. Obama’s overall approval rating for 2014 is on a par with his overall approval rating for 2010, which is a good sign for the GOP. Obama’s strong approval rating is running well below the pace of four years ago, which is a very good sign for the GOP.
The third indicator (red lines) represents Obama’s strong-approval quotient (fraction of likely voters who strongly approve/fraction of likely voters who approve) divided by his strong-disapproval quotient (fraction of likely voters who strongly disapprove/fraction of likely voters who disapprove). I call this the “enthusiasm” indicator. Higher values represent greater enthusiasm for Obama; lower values, less enthusiasm.
The green points (connected by lines) are plots of Obamacare’s standing, as measured by the ratio of strong approval to strong disapproval among likely voters. Obamacare is faring worse in 2014 than it did in 2010 — another good sign for the GOP.
Obama’s overall approve/disapprove ratio is about the same as it was in the runup to the 2010 election, but Obama is faring worse this time around with respect to strong approve/disapprove, enthusiasm, and Obamacare. As of now, the indicators herald a repetition of the GOP’s resounding victory in the 2010 mid-term election. As of now, I expect the GOP to claim a 50-seat majority in the House and control of the Senate (if only by 51-49).
