Talk Elections

Henrico VA
Prince William VA
Mecklenburg NC
Gwinnett GA
Cobb GA
Hillsborough FL
Orange FL
Osceola FL
Hamilton OH
Orange CA
San Diego CA

What else am I missing?

Racial demographics were a major factor in the partisan shift of these counties, but it cannot be denied that there was a substantial number of voters-moderate suburbanites who voted for Romney and/or George W. Bush, who moved towards the Democrats in recent years. In Orange County, and in San Diego County, this is certainly true. Even in Cobb and Gwinnett, there were many Romney-supporting suburbanites who shifted Democratic in 2016 and particularly last year. Henrico and Prince William are counties full of moderate suburbanites who have soured on Republicans in recent years.

-Cobb and Gwinnett went from 90% white in the early 90s to around 45% white now. In GA, Republicans get around 75% of the white vote, but due to the increase in minorities, the state has gotten tighter in recent years. So GA's transformation is purely due to racial demographics. VA is different as the primary catalyst is the influx of college-educated white liberals into northern VA.

-OC and SD are a functin of both racial demographics and white suburbanites, but the correlation between GOP vote share and % of whites, is pretty hard to deny.

-There's a very good reason why Democrats want mass immigration and citizenship for illegal aliens. It's about winning elections.

Clayton County, Georgia
DeKalb County, Georgia

I did say that racial demographics were a major factor in the transformation, but it's hard for me to see Republicans still obtaining Bush 2004 numbers among white suburbanites.

Broward County, FL was solidly Republican in 1972 at the local level.  It was not until the late 1980s that Broward swung to the Democrats due to demographic changes.  Today, Broward is the most Democratic County in Florida.

Correct. At the presidential level, Broward went GOP from 1952 through 1972. It went for Carter in 1976 and then Reagan twice and HW Bush in 1988. It has been solid Dem since 1992.

It is interesting to note that Miami-Dade/Broward/Palm Beach were the first Florida counties to go GOP in the 1950s due to the influx of Northern migrants who were attracted to the GOP's pro-business policies and the lack of plantation based slavery in that area before the Civil War.

Rockdale County, GA. Went from 73% non-Hispanic White in 2000 to 41% in 2010, to 35% in 2017. GOP share of the vote has dropped in each election, from 62% in 2000, to 35% in 2016.

Over the past two décades some of the most obvious examples would be :

Virginia :
Henrico County
Prince William County

North Carolina :
Forsyth County

Georgia :
Gwinnet County
Cobb County
Henry County
Douglas County
Newton County
Rockdale County

Florida :
Osceola County
Orange County

Texas :
Fort Bend County
Harris County
Bexar County
Dallas County

Illinois :
Kane County

Alabama :
Jefferson County

California :
Fresno County
Riverside County

Gwinnet swung to the left between 2008 and 2012, so it's mostly demographic changes

+Rockdale, Newton, Henry and Douglas.

By 2030, possibly also Fayette

I'd also throw in San Bernardino County.

And although not "100% purely" as the title says, count me in for including Orange County. Even before Trump was the nominee, I thought it'd flip. GOP-Hillary voters certainly made it a wider margin than even I expected, though

Great list. If it weren't for mass immigration, the GOP would be crushing presidential elections.

GA however is not due to Latino immigration but blacks from the northeast and midwest fleeing to GA due to cost of living.

Hamilton OH didn't change in racial demographics, but higher voter participation among blacks probably contributed.

While I'm sure Forsyth NC has become slightly more minority over the years, it doesn't seem to really fit on this list.  The decline of big tobacco along with decent educational attainment seems to be a bigger factor.