How did Democrats win the popular vote by 9 in the 1978 midterms?

[The Economy is Getting Worse]

Carter's popularity was only in the 30s, and inflation was high. Despite this, Democrats won the popular vote by 9 and won 277 House seats and 58 Senate seats. How did this happen? Why did Carter's numbers not translate downballot in 1978?

It should be noted that in 1980, Reagan actually had coattails.

[Amenhotep Bakari-Sellers]

Due to Watergate the same thing is Happ to Rs due to J6 R party doesn't commit crimes they commit Treason and Reagan kept losing seats in Congress because of Iran Contra

[Sir Mohamed]

Weren't there a lot of races in which Dem candidates ran unopposed? Especially in parts of the South, where Southern Dems still had a major impact downballot? Remember than the GOP's rise in the South lagged behind presidential results a few cycles (at the state level, it wasn't until around 2002 the GOP took over most elected offices). With the conservative Southern wing, Dem House majorities even were able to survive 1972, 1980 and 1984.

Due to unopposed races, the House NPV actually almost pointless. In addition, local brands for certain candidates and ticket splitting was a much bigger factor back in the day.

[TML]

Remember that 1932-1994 was a time period where Democrats mostly dominated Congressional races, and 1978 was no exception.

[Vosem]

Democrats had a large number of popular incumbents, so even though they fell a pretty normal distance they still ended up winning the popular vote by 9 points.

Popular vote shift between presidential-year House generic ballot and next midterm, relative to presidential party performance (if this makes sense):
2022: -6 (D+3 to R+3)
2018: -9 (R+1 to D+8)
2014: -6 (D+1 to R+5)
2010: -17 (D+10 to R+7)
2006: -10 (R+2 to D+8)
2002: +4 (R+1 to R+5)
1998: -1 (D+0 to R+1)
1994: -12 (D+5 to R+7)
1990: -1 (D+7 to D+8)
1986: -5 (D+5 to D+10)
1982: -9 (D+3 to D+12)
1978: -5 (D+14 to D+9)
1974: -12 (D+5 to D+17)
1970: -8 (D+1 to D+9)
1966: -12 (D+15 to D+3)
1962: -5 (D+10 to D+5) -- underrated similarities to 2022, actually; the size of the backlash was normal but Republicans failed to connect anywhere
1958: -10 (D+2 to D+12)
1954: -5 (D+1 to D+6)
1950: -7 (D+8 to D+1)
1946: -14 (D+5 to R+9)
1942: -9 (D+5 to R+4)
1938: -15 (D+16 to D+1)
1934: +1 (D+12 to D+13)
1930: -7 (R+15 to R+8)
1926: +1 (R+16 to R+17) -- didn't know about this one
1922: -16 (R+23 to R+7)
1918: -7 (R+2 to R+9)
1914: -5 (D+4 to R+1)
1910: -5 (R+5 to D+0)
1906: -7 (R+14 to R+7)
1902: -2 (R+7 to R+5)
1898: -3 (R+8 to R+5)
1894: -16 (D+6 to R+10)
1890: -6 (D+2 to D+8)
1886: +0 (D+3 to D+3) -- really D+2.9 to D+3.1
1882: -4 (D+3 to D+7)
1878: -0 (D+5 to D+5) -- really D+4.8 to D+4.6
1874: -15 (R+10 to D+5)
1870: -2 (R+7 to R+5)

...before this gets weird, because you have a Republican victory in 1864 but then a backlash to a Democratic President in 1866. Many of the 1850s elections are also hard to parse because of the frequent emergence of new parties, so Democratic popular vote margins tend to grow even as their actual numbers in the House shrink.

Across the 20th century, the average size of a midterm backlash (roughly; weird errors from lots of rounding guaranteed) was almost exactly -7. 1978 is a little bit smaller than that, but it isn't a huge outlier or anything. I initially thought that the backlashes were getting more intense over time, but it turns out that's just me being bad at looking at things before doing the math: not only is the 1900-2000 average -7, but the 1900-1950 and 1950-2000 averages are both also -7. At the moment the 21st century average (2000-2022) is also -7.

[TheElectoralBoobyPrize]

One point more than they won it by in 2006 & 2018 with an unpopular Republican in the White House, but the GOP had strength in the South in those elections that they didn't have back then.

Not only was this the last time the Democrats won a House majority under a Democratic President, they didn't even come close to losing it. They still had way, way more House seats than they had before 1974.

It is worth mentioning that they won the House popular vote by 14 points in 1976, so there was still a dramatic swing in favor of the GOP even while they were still being associated with Nixon and Watergate.

[Roll Roons]

What people have said about the rural white South is definitely true, but there’s also the fact that a lot of Northern cities (NYC, Chicago, Philadelphia, Detroit, Cleveland and more) probably had a lot more congressional seats than they do today.

[○∙◄☻¥tπ[╪AV┼cVê└]

They even won 1972 and 1984 by 5-6%.