There's no question that Obamacare hurts the prospects of Democratic candidates in 2014. The question is how much -- and where? Last week I wrote a blog post comparing President Obama's Gallup job approval numbers for calendar year 2013 in all 50 states and the District of Columbia with Obama's 2012 percentage of the popular vote there (which tracked closely his November 2012 job approval). I found the biggest declines in almost all the 2012 target states, most of which have 2014 Senate races which at the beginning of the cycle did not appear to be competitive but which appear so now in recent polling.

The precarious position of Democrats in their battle to hold onto a Senate majority has been further underlined in the recent Senate race polls conducted by Republican firm Harper Polling for the pro-Republican group American Crossroads.

Those show Republicans leading in four Democratic-held seats in states that gave Mitt Romney significant margins — Mead Treadwell 47 percent to 41 percent over incumbent Mark Begich in Alaska; Tom Cotton 42-36 over incumbent Mark Pryor in Arkansas; Bill Cassidy 45-44 over incumbent Mary Landrieu in Louisiana (even though 46 percent said they are not sure of their opinion of Cassidy); and Steve Daines 43-29 over John Walsh (appointed to the Senate on Friday to replace Max Baucus).

In target states, Harper had former Secretary of State Terri Lynn Land 42-37 over Rep. Gary Peters in Michigan; state House Speaker Thom Tillis tied 44-44 with incumbent Kay Hagan in North Carolina; and incumbent Jeanne Shaheen 40-35 over former Sen. Scott Brown. It’s a sign of trouble for an incumbent when he or she runs under 50 percent in a state, and it’s a sign of very serious trouble when an incumbent is running behind a challenger, as Begich, Pryor and (by a statistically insignificant 1 percent) Landrieu are in these polls.

The following table shows for each state Obama's percent of the vote in 2012, his 2014 approval percentage in the Harper poll, the difference between them and the Harper 2014 pairings referred to above.

State Obama 2012 approval Obama 2014 approval Change Dem candidate's percentage GOP candidate's percentage Alaska 41 31 -10 41 47 Arkansas 37 31 -6 36 42 Louisiana 41 40 -1 44 45 Michigan 54 38 -16 37 42 Montana 42 36 -6 29 42 New Hampshire 52 35 -17 40 35 North Carolina 48 43 -5 44 44

Note that current Obama approval has fallen farthest behind 2012 election percentages in the two target (or semi-target) states, Michigan and New Hampshire, and it has fallen by smaller amounts in non-target Alaska and Montana, which saw almost no presidential campaign activity in 2012. It has fallen least in the three Southern states, where we can reasonably assume that it has stayed high among those states’ black voters and was already pretty low among white voters in 2012 (especially in Louisiana, which has the second highest black percentage of any state and where Obama ran very poorly among whites). Four incumbent Democrats — Begich, Pryor, Landrieu and Shaheen — run four to 10 points ahead of Obama approval; Hagan, who started off far less well known, runs only an insignificant 1 point ahead. Preliminary conclusion: It’s going to be hard for these Democrats to win if Obama’s numbers stay as low as they are today or unless (perhaps a likelier possibility) their Republican opponents do something stupid.

What about House races? It has generally been assumed, and for good reason, that Republicans have little possibility of substantial gains because they did so well in 2010, when they won 242 seats, more than in any election since 1946, and in 2012, when they won almost as many, 234. And it has been noted that the retirement of incumbent Republicans in Iowa's third district, New Jersey's third, Pennsylvania's sixth and Virginia's tenth give Democrats a good chance of winning some seats, on top of California's 31st (where California’s all-party primary law left the 2012 race as a contest between two Republicans in a 57-percent Obama district). Against that must be weighed Republicans’ near certain chance of picking up North Carolina's seventh and Utah's fourth, where Democratic incumbents who won by one percent in 2012 retired, in districts where Mitt Romney won 59 and 68 percent of the vote.

Now, however, the National Republican Congressional Committee has released four polls, also conducted by the Republican Harper firm, which suggest that Obama's weakening job approval and the negative reaction to Obamacare may be expanding the field to the Republicans' advantage. Paul Kane of the Washington Post has the story. The following table gives the numbers corresponding to those in the Senate race table above.

District Obama 2012 vote Obama 2014 approval Change Dem candidate's percentage GOP candidate's percentage Calif. 26th 55 38 -17 42 44 N.Y. 3rd 51 39 -12 42* 43* N.Y. 21st 52 32 -20 34* 46* Wash. 1st 54 40 -14 43* 46*

* = poll based on generic ballot

The Democratic incumbents in California's 26th and Washington's first — Julia Brownley and Suzan DelBene — are freshmen, elected in seriously contested races in 2012 by 53-47 and 54-46 margins respectively, tracking almost precisely Obama’s 54 percent in both districts. Brownley, matched against a named opponent, runs ahead of current Obama approval by four points but well under 50 percent, like most of the senators listed above. Generic ballot questions (Republican candidate vs. Democratic candidate) were asked in the other three districts, where no well-known Republican challenger has emerged. In all three, the generic Democrat runs just two to three points ahead of current Obama approval. There is not likely to be a serious race in New York's third on Long Island, where incumbent Steve Israel is Chairman of the Democratic Congressional Campaign Committee. But there is certainly likely to be one in the Upstate 21st, where incumbent Bill Owens, first elected in a November 2009 special election, is retiring.

These results provide support for the proposition that Republicans could win a fair number of House seats not previously thought to be in play — though it should be kept in mind that these are polls conducted by a Republican firm for a Republican party client, and that the NRCC may be sitting on results in other districts that look less favorable for their side. No political operatives have an obligation to reveal unfavorable poll results, and very few do. It should also be said that polling Steve Israel’s district shows a certain puckishness and perhaps, in some Democrats’ minds, childish prankery; he won his last race 58-42.

Having said that, it’s worth noting that there are 40 House seats currently held by Democrats in which Obama received 55 percent (rounded off) or less of the vote in 2012; nine of them were carried by Mitt Romney. Some of those are already targeted by Republicans, including New York's 21st, Massachusetts' sixth (where there are scandal issues), New Hampshire's first and second (where a recent WMUR/UNH poll showed the Democratic incumbent trailing in the first and only barely ahead and well under 50 percent in the second) and others. What I find interesting here is that relatively few are in 2012 presidential target states. They include the two districts in New Hampshire, North Carolina's seventh (pretty much a gimme for Republicans) and Florida's 18th, 22nd and 26st. Four target state districts which barely make the 55-percent cut don’t seem to me likely to be seriously contested (Nevada's fourth, New Mexico's first, Pennsylvania's 17th and Wisconsin's third).

Interestingly, most of these seats are in politically virgin territory — virgin in the sense that they have not seen thousands of gross ratings points of presidential campaign ads and have not been the scene of intensive organized and personalized campaigning by the Obama campaign or any other presidential effort. Six of these districts are in California (which saw only one of its 53 districts switch parties in the five elections between 2002 and 2010), three in Arizona, two in Oregon and one in Washington. The district lines in California, Arizona and Washington were drawn by supposedly nonpartisan redistricting commissions, gamed successfully by Democrats in California and Arizona, but still yielding more marginal seats than in the previous decade.

Political handicappers Charlie Cook and Stuart Rothenberg put 23 of the 25 districts on their lists of possibly endangered seats; the exceptions are New York's third with Israel and longtime incumbent Peter DeFazio in Oregon's fourth. But they put only seven of the 15 Obama 54- and 55-percent on their lists, and only two of them above their bottom tiers of contestable seats: New Hampshire's second2, which flipped back and forth in 2006, 2010 and 2012, and Massachusetts' sixth, where the Democratic incumbent has scandal issues. There are 36 districts where Obama won between 56 and 59 percent; only 9 of them show up on either Cook's or Rothenberg's list. The interesting question, then, is whether Republicans can expand the political battleground in House races as they seem to be doing in Senate races. Unclear at present.