Why the electoral battlefield is expanding

CNN/Stylemagazine.com Newswire | 4/24/2018, 7:47 a.m.
The surveys, which point to strong Democratic opportunities to capture Republican-held Senate seats in Arizona and Texas, might prove to ...
Rep. Kyrsten Sinema of Arizona and Rep. John Barrow of Georgia on Capitol Hill.

Analysis by Ronald Brownstein, CNN

(CNN) -- Two recent polls indicating surprising Democratic strength in Senate races across the Southwest underscore how the parties' shifting demographic and geographic bases of support are widening the electoral battlefield.

The surveys, which point to strong Democratic opportunities to capture Republican-held Senate seats in Arizona and Texas, might prove to be desert mirages by Election Day. But even the prospect of close Senate races in those ordinarily Republican-leaning states, shows how old political alignments are cracking as the parties build new coalitions of support.

In that way, this fall's possible Democratic gains across the Southwest represent a kind of bookend to Donald Trump's Rust Belt breakthrough in 2016, when he narrowly captured three "blue wall" states that had voted Democratic in every presidential race since at least 1992: Michigan, Wisconsin and Pennsylvania.

Each development suggests that after years in which the parties seemed to partition the country into impenetrable spheres of influence, more states may be within reach for both sides. And that could produce a more unpredictable politics that forces both parties to fight across a wider battlefield than either has usually faced in recent years.

This volatility is rooted in the shifting basis of each side's electoral coalition. Beginning before Trump, but accelerating under him, Republicans have established a commanding edge among older, blue-collar, non-urban and evangelical whites. That advantage is strengthening the GOP's long-term position in Midwestern, Appalachian and Great Plains states that remain preponderantly white, heavily blue-collar and still largely dependent on manufacturing, resource-extraction and agriculture for jobs.

Starting in the 1990s, but accelerating since Barack Obama's first election, Democrats, conversely, have grown increasingly reliant on a coalition of young people, minorities and college-educated, secular and single whites, especially women. That is slowly strengthening the party's position in Sun Belt states that are growing more racially diverse, and are also in many cases transitioning faster than the mostly-white heartland states into the post-industrial, information-age economy.

Over the long term, these shifts will likely mean that Republicans win more elections than they do today across Rust Belt states such as Ohio, Iowa and Michigan, and Democrats will make deeper inroads across Sun Belt states from Georgia and North Carolina to Arizona and Nevada.

But the effect today is very different. While these parallel changes are in midstream, they are creating a more competitive balance in both the Rust Belt and the Sun Belt. The result is that the 2018 midterm election and the 2020 presidential race will each likely produce a procession of closely contested races on both fronts.

The 2016 presidential election offered a revealing snapshot of how the partisan balance is evolving in both the Sun Belt and Rust Belt. One way to measure the change is to compare the 2016 presidential outcomes in both groups of states to the results in 2008, when Obama won his sweeping first victory.

Obama won the popular vote over John McCain by a national margin of almost 7.3 percentage points. In 2016, Hillary Clinton beat Trump in the national popular vote by 2.1 percentage points. That means from the apex of 2008 through 2016, the Democratic margin in the national popular vote declined by about 5.2 percentage points.