These were a disaster for the Democratic Party, which took a pounding and lost the House of Representatives. The Democratic share of the vote plummeted, hurt by a weak economy and unpopular policies:
|2010 House Elections
|2008 House Elections
|2008 Presidential Election
In this rightward shift, everybody voted more Republican than in 2008. Every region of the country was redder. Women voted more Republican. Men did. Republicans did. Independents did, especially so. Democrats did too. With regards to ethnicity, Americans of every race and nationality voted more Republican. Hispanics did. Asians did. Native Americans and Pacific Islanders did. Whites did, very much so.
So did blacks:
|Black Vote: 2010 House Elections
|Black Vote: 2008 House Elections
|Black Vote: 2008 Presidential Election
Now, this table obviously shows that blacks still voted very Democratic in 2010. The point, however, is that - like everybody else - blacks also shifted Republican in 2010. The presence of President Barack Obama did not magically prevent Republicans from gaining black votes in 2010.
It is true that Republicans gained less amongst blacks:
||2010 Republican Improvement From...
||2008 House Elections
||2008 Presidential Election
Partly this is because blacks are a highly Democratic constituency. When the nation as a whole shifts Republican, highly loyal Democrats move less rightwards than the average. Partly this is due to Mr. Obama's popularity amongst blacks.
Without this rightward shift in the black vote, however Republican victories in Illinois or Pennsylvania's senate races would have been a lot closer - or turned into losses altogether. The same holds true for close Republican victories in the Ohio and Florida gubernatorial elections. Democrats would probably hold a handful more House seats, from North Carolina's 2nd congressional district to Alabama's 2nd congressional district.
If Republicans had done the same amongst blacks as they did in 2008, Democrats would have won a number of races they lost. The Republican gain amongst blacks played an important part of their overall national victory.