Rep. Lucy McBath (D-Ga.) recently announced that in 2022, she would run for Congress in a different congressional district after Georgia’s state legislature redrew her 6th district to include significantly more Republican-friendly territory. McBath will instead run in the new 7th district, which Joe Biden won by 16 points in 2020.

The bad news? The seat is already occupied by her Democratic colleague Rep. Carolyn Bourdeaux, who has shown every indication of running again in 2022. The two incumbents will face off in a Democratic primary. In fact, this incumbent-vs.-incumbent matchup is the third announced so far in this redistricting cycle.

More such matchups could emerge over the next year as other states finish drawing new district maps.

But is a district’s partisan makeup — how much its voters lean toward Republicans or Democrats — the only thing that matters in congressional elections? Not exactly. My research shows that specifics about each candidate continue to make a difference — and, in particular, whether incumbents have deep roots in the communities they represent. These connections to place matter enormously to voters. And if incumbents want to win reelection, they should probably pay attention.

Some politics is still local

Pundits and analysts tracking redistricting have focused largely on how redrawn congressional districts favor one party or the other, based on how residents voted in previous presidential elections. But districts are more than just head counts of Democrats and Republicans. They are dynamic places with unique histories, industries, businesses, cultures and traditions that are defined by much more than their partisan biases. Successful candidates and representatives recognize this, which is why they try to avoid carpetbagging whenever possible.

The politics of place are particularly important in an institution like the U.S. House, where boundaries shift often. Some incumbents are deeply rooted in their districts, while others are far less so. My forthcoming book explores the depth of legislators’ biographical history in the districts they represent. My research has included gathering community data on everyone who served in Congress from 2002 to 2020, including whether they were born, went to school, or established local businesses within their district boundaries.

I found that these local connections gave them serious boosts in their reelection efforts, and changed how they campaigned and communicated with their voters. Local roots have practical benefits, such as increasing authentic, homegrown name recognition for incumbents who have them. They also bestow symbolic benefits, such as giving voters the sense that an incumbent shares what political scientist Kal Munis calls their “place identity,” or a feeling that their representative is like them in ways that go beyond partisanship.

Local roots and incumbency in Congress

Most members of Congress do currently live in their districts, although they are not constitutionally required to — but since 2002, less than half have actually been born within their district boundaries, and only about 55 percent attended high school there. About a fifth have run a local business in the district, and about 60 percent got their college degree within their home state.

I combined these and similar factors into what I call a Local Roots Index to be able to measure the depth of each member’s roots. As you can see in the figure below, some incumbents are deeply rooted in their local communities, while many others are not.

These factors have major implications for redistricting. Few observers take note of individual members of Congress’s local roots, or consider how redistricting might sever or consolidate this advantage. Many pay attention to the fact that when districts change, incumbents often face voters who are friendlier or more hostile toward their party. But they also face more or less familiar electorates. Political scientists have shown, for example, that incumbents perform better after redistricting when their new districts retain more of the previous district’s voters, even after accounting for partisan balance.

Similarly, when district lines change, members of Congress can be dispossessed from their native community. Incumbents might be deprived of the cities and towns in which they grew up, went to high school or college, or built their professional reputations.

This can spell electoral disaster. Incumbents facing these redistricting-specific changes suffer at the ballot box, my research finds, and are often forced to run very different kinds of campaign operations and spend more reelection funds in response — even when a district’s partisan makeup remains the same.

This is particularly important when two incumbents face off in a primary. In a recent paper, I found that incumbents with deep local ties enjoy a several-point advantage against members of the same party, and are less than half as likely as their carpetbagging counterparts to attract a challenger in the first place.

Carpetbaggers should be concerned about 2022

These findings should interest at least one of the double-incumbent pairings that have already emerged: West Virginia Reps. David B. McKinley and Alex Mooney, both Republicans. McKinley was born and raised in Wheeling, and founded a business there after getting his college degree. Mooney, on the other hand, is the very model of a carpetbagger: He held a seat in the New Hampshire state legislature, moved to Maryland for an unsuccessful run for Congress there, then moved again to West Virginia in 2014 before finally winning his 2nd district seat less than two years later.

Mooney’s carpetbagging has cost him votes and money. While McKinley has stayed consistently even with or ahead of Republican presidential counterparts such as Mitt Romney and Donald Trump in his 1st district, Mooney has run far behind Trump in his 2nd district, twice by more than 20 points. He’s also had to spend far more than McKinley to hang onto his seat over the past two cycles.

In races between well-known incumbents, particularly ones with the same party label, every point counts. Knowing a district’s party leanings helps in handicapping the parties’ chances of holding seats. But candidates’ connections to their districts matter as well.

Charles Hunt (@charlesrhunt) is an assistant professor of political science at Boise State University whose book “Home Field Advantage: Roots, Reelection, and Representation in the Modern Congress will be published by University of Michigan Press in 2022.