2014 U.S. House, Overall Win Margin
Daily Kos Elections is pleased to present a comprehensive look back at the 2014 election results, illustrated with a broad range of fully interactive maps and data visualizations. The above map, for instance, shows the 2014 U.S. House results by overall winning margin between Democrats and Republicans, with Democrats in blue Republicans in red. Click on a district and you will find info about the winner of each district, the 2014 election results, and the 2012 presidential results as calculated by Daily Kos Elections. The full-screen versions of this and the House maps below also have a map legend.
Aside from uncontested seats, the largest winning margins for each party were Democrat Nydia Velázquez's 80 point win in New York's 7th district and Republican Mac Thornberry's 72 point win in Texas' 13th district. Arizona's 2nd district was the closest race of 2014, with Republican Martha McSally defeating incumbent Democrat Ron Barber by just 0.07 percent.
The interactive scatterplot below illustrates the very strong relationship between 2012 presidential and 2014 House performance. Hover over a dot and you will find the district winner and basic result stats, utilizing the two-party-only vote. Outliers to the top and left saw Democrats overperform, while those to the bottom and right saw Republicans do so.
2014 U.S. House Democratic Vote vs. Obama 2012
The non-interactive version also provides a line of best fit. There's very little variation around the best-fit line, as the two election outcomes were highly correlated. Presidential performance in 2012 was the single most informative predictor 2014 congressional outcomes.
Head below the fold to see more maps on the House as well as similar visualizations for the Senate.
House and Presidential Winner by District
Just as we did for our collection of maps by presidential and state legislative winner, this map details which party won each district for president and U.S. House. Thanks in large part to Republican gerrymandering, Mitt Romney carried 226 districts to just 209 for Barack Obama.
The 183 districts in solid blue voted for Obama and a Democrat while the 221 in solid red went for Romney and a Republican. The 26 light red seats voted for Obama and elected a Republican, while five seats in light blue went for Romney but elected a Democrat in 2014. In total, Republicans won 247 seats to 188 for Democrats, their largest majority since 1928.
Bob Dold holds the bluest seat of any Republican, with his suburban Chicago seat voting for Obama 58-41. Collin Peterson sits in the reddest seat of any Democrat, a rural Minnesota district that supported Romney 54-44.
Two-Party Swing from 2012
This map compares the 2014 Democratic share of the vote with 2012, excluding minor parties. Redder seats went more Republican, while bluer seats voted more Democratic. The 105 blank districts lacked both major parties on the ballot in at least one of 2012 or 2014 and make for a poor comparison.
The largest swing toward Democrats was 18 points in West Virginia's 2nd district, which Republican Alex Mooney nearly lost after Shelley Moore Capito departed to successfully run for the Senate. New York's 27th district swung 20 points to incumbent Republican Chris Collins, thanks to his no longer facing a serious opponent and turnout in New York being the second lowest of any state.
2014 U.S. House Democratic Vote vs. 2012 House
The swing from 2012 to 2014 was close to uniform: districts shifted in the Republican direction by about three to to four percentage points on average. Interestingly, there was no relationship between 2012 presidential vote share and the House vote share swing. Most districts swung Republican regardless of partisanship, rather than having a swing proportional to each party's relative strength.
Two-Party House Democratic Vote Minus Obama 2012
Accompanying the first scatter plot, this map shows the difference in two-party vote share between Democrats in 2014 and Obama in 2012. Bluer districts saw the Democrat perform better than Obama, while redder districts saw them do worse. The 77 blank districts lacked both parties on the ballot last year, a higher number than any of the last several cycles.
The best overperforming Democratic winner was Patrick Murphy in Florida's 18th district, with 12 percent more of the two-party vote than Obama. For Republicans it was Pete King in New York's 2nd, with a whopping 22 percent more than Romney. Among the worst underperforming winners, Democrat Mark Takai in Hawaii's 1st won 19 percent less of the vote than Obama. Republican Mia Love in Utah's 4th did 16 points worse than Romney, in part thanks to his pro-Mormon bump in 2012.
2014 U.S. Senate, Overall Win Margin
Moving on, here is the Senate by overall winning margin. Zoom out to see Alaska and Hawaii, or you can view the full-screen versions of this chamber instead. Oklahoma and South Carolina each had two simultaneous elections thanks to special elections. Those races make up the southeast portion of each state while the northwest denotes the regularly scheduled election. Also note that for the Kansas Senate race, independent Greg Orman is counted as a Democrat since he was the de facto nominee.
Ignoring uncontested seats, each party's widest margins were 42 points for Democrat Brian Schatz in Hawaii and 55 points for Republican Mike Enzi in Wyoming. The closest Senate race was surprisingly Virginia, where Democrat Mark Warner squeaked by with a 0.8 point win despite most prognosticators rating him as the clear favorite.
Senate and Presidential Winner by State
Republicans won all 21 seats carried by Romney, along with three that went for Obama. Democrats only won 12 seats last year, all of which voted for Obama. The bluest seat Republicans won was Susan Collins' Maine, which Obama won 56 to 40. The reddest seat Democrats held was Mark Warner's Virginia at 51 to 47 for Obama.
In total Republicans hold a 54 to 46 majority, with 11 Republicans in Obama states and five Democrats in Romney sates. Joe Manchin in West Virginia holds the reddest seat of any Democrat at 62 to 35 for Romney. Mark Kirk in Illinois has the bluest one of any Republican at 57 to 41 Obama.
Two-Party Swing Since Last Election
Because of several vacancies and special elections since 2008, this map is of vote swing since the last election for each seat. Thus, several seats stand out as bluer compared to 2010 or a special election. Despite the wave however, Republicans still did worse in five states compared to 2008: Kansas, Minnesota, Mississippi, Oregon, and Tennessee. Oregon swung furthest toward Democrats, with Jeff Merkley winning eight percent more of the vote.
Of course, many states swung drastically to the right. Republican Steve Daines won 32 percent more of the vote in Montana for his party than their 2008 nominee at the most extreme. South Dakota and West Virginia weren't too far behind, which is unsurprising since Democrats triaged all three of these seats where their incumbents retired after 2008 blowout wins. Note that Arkansas is omitted because it lacked a Republican in 2008, while Alabama lacked a Democrat in 2014 for the first time since Reconstruction.
Two-Party Senate Democratic Vote Minus Obama 2012
This final map compares the 2014 Senate Democratic vote with 2012 president. Unlike the House, all but one race saw less than a 10 percent difference in vote shares. Maine's Susan Collins stands out as an extreme outlier and the widest gap of any congressional race, with her having won 26 percent more of the two-party vote than Romney. Rhode Island Democrat Jack Reed ran furthest ahead of Obama, with seven percent more of the vote.
2014 U.S. Senate Democratic Vote vs. Obama 2012
This last scatter plot graphs the previous map, with a non-interactive version with a linear regression line here. It may at first appear that the relationship between Obama's 2012 state-level vote share and the Democratic candidate's senate vote share in 2014 is weaker than in the House. However, this is wholly due to Maine. Without Susan Collins, the strength of the relationship is equivalent, indicating that there is very high correlation between presidential and congressional voting, in both chambers. Expect this pattern to get even stronger in the future as ticket splitting continues to decline while polarization increases.