Monday, April 10, 2023

Putting Tricia Cotham's Party Switch in Context

By Christoper Cooper and Michael Bitzer

Donald Trump's indictment might have received the most political attention last week and Democrats won a critical state supreme court race in Wisconsin, but the most politically consequential event in the United States might have taken place eight hours away from the eye of the Trump storm. On April 5, 2023, Tricia Cotham, a Democratic lawmaker in North Carolina's State House, announced that she was switching political parties. Elected as a Democrat, Cotham is now a Republican.

Cotham's move essentially rendered Governor Cooper's veto ineffective. The Republicans now have supermajority control of both chambers of the North Carolina General Assembly and can override Cooper's veto without securing a single Democratic vote. 

The news about Cotham raised all sorts of questions about party switching in general, and how it potentially fits into a seismic shift in North Carolina politics.

Although legislative party switches like Cotham's are uncommon, they are not unheard of. According to Political Scientist Boris Schor, 427 state legislators switched political parties between 1989 and 2020. The majority of these switches took place in the Southern United States, with the vast majority leaving the Democratic Party for the Republican Party. This fits with the broader story of partisan change in the U.S. South.

Of course, Cotham's switch is not only significant because she switched, but because her switch changed the North Carolina House of Representatives from Republican control to Republican supermajority control. While most switches do not have such broad reverberations, some do. In 2002, Georgia state representatives Lee, Cheek and Bowen switched from the Democratic to the Republican Party, changing the chamber from Democratic to Republican control, a status that has remained ever since. A similar story played out in Mississippi as State Senator James Walley switched from the Democratic to the Republican Party, leaving the chamber deadlocked.

Which brings us to North Carolina.

What About Party Switchers in the Old North State?

Several members of the North Carolina General Assembly have flipped their party affiliations since 1995. Most notably, Michael Decker, a Republican representative from Forsyth County, created a political firestorm when he switched to being a Democrat. In doing so, Decker swung a 61-59 Republican state house majority in the 2003 legislative session to an even 60-60 tie between the two parties, with a subsequent deal cut that allowed the Democratic leader Jim Black and Republican Jim Morgan to serve as 'co-speakers' for state house. 

Ultimately, this switch became the basis of criminal investigations, one of which culminated in Decker pleading guilty to accepting a $50,000 illegal contribution from Jim Black, in exchange for switching parties and supporting Black, and Black's subsequent conviction on corruption charges. The bribe, as North Carolina politics veterans know, took place in a Salisbury, North Carolina IHOP restaurant bathroom (sometimes truth really is stranger than fiction).

More recently, state representative Paul Tine switched from being a Democrat to an unaffiliated legislator in 2015. Critically, after his switched, he caucused with the Republican majority. In making his decision, Tine said that "he wanted to say within the moderate Democratic fold, but he felt that the party was veering too far to the left for him." After his switch, he chose not to run for re-election.

Two years later, state representative Bill Brisson also switched parties, shifting from the Democratic to the Republican side of the aisle. Brisson explained that "[a]ll of my district is rural, and a lot of my constituents are. I've been getting a lot of pressure from my constituents in the past few years to change. I don't have a lot in common with the Democratic Party right now because they have become so liberal."

What the Research Tells Us About Party Switchers

Political Science research on party switchers offers some clues about what constitutes a "normal" party switch. There is considerable evidence that many party switchers take the action because they have progressive political ambition (they want to run for higher office). This, of course, makes sense. If you find yourself in step with the people who currently represent you, but out of step with the people who might vote for you for the next step on the political latter, you might switch parties (see Antoine Yoshinaka's Crossing the Aisle for the best book-length treatment of this idea).

Not surprisingly, some legislators switch parties after redistricting. If a legislator's old district doesn't look like their new district, they might change parties to increase their odds of reelection. Others switch after a new party takes over control of the chamber. The logic here is simple: if you want to pass policy, you're better off being in the majority party. 

Then there's the question of ideology. Do legislators switch parties not because of progressive ambition or reelection motivation, but because they find themselves ideologically out of step with their parties? There is some evidence of that motivation, particularly in the American South where conservative Democrats, once common, are now about as common as four leaf-clovers on the North Pole. These conservative Democrats may choose to exit the party for a home where they find more ideological allies. 

So, how does Cotham's switch fit with these explanations?

How Does All of This Square With Cotham's Switch?

Two political scientists, Bors Shor and Nolan McCarty, have studied the ideological mapping of America's state legislatures. In doing so, they created a database of roll-call votes in the nation's state houses and assemblies to locate individual members, and their respective parties and chambers, along an ideological spectrum, and thus create a comparative score for each member and chamber/party.

Below, you can see the ideology scores of all members of the North Carolina General Assembly. Lower scores represent more conservative voting patterns and higher scores (to the right) represent more liberal voting. The boxes represent actual legislators put into bins. The solid line that looks like two hills is a summary of the boxes. As you can see, the North Carolina General Assembly mostly consists of two normal curves with a few legislators on the extremes and a few in the middle. Tricia Cotham's expressed ideology is represented by the vertical dotted line.

The takeaway here is that Tricia Cotham's previous voting record is towards the moderate end of the Democratic Party, but, at least until this point, she is not "out of step" with her Democratic colleagues. 

What Will Happen Now?

The figure above, while helpful, ignores change over time. The next figure shows North Carolina's state house party scores between 1995 and 2018. Once again, positive scores on the axis indicates more conservative ideology, while the negative scores indicates more liberal ideology. Based on the two solid lines (red for Republican caucus, blue for Democratic caucus), before 2008, the parties were fairly consistent in their line, but after 2008, the parties have moved further away from each other to the ideological extremes. This is a likely sign of the 'sorting' that political parties and their members have undergone in recent years. 

Data from Schor (2020); Graph by Michael Bitzer.

We also map two of the party switchers since 1995, Bill Brisson and Paul Tine. In Brisson's case (the round-marker dark red line), he was obviously a very conservative Democrat, in the fact that he was in the positive conservative territory from 2007-2017, and when he switched parties, he moved even more closely aligned to his new fellow Republicans. 

For Tine (represented in the square-marker purple line), his first two years in the state house showed him with a negative score, but there was distance between himself and his fellow Democrats. With his switch to unaffiliated and caucusing with the GOP, Tine moved more conservative, but not as closely with his new colleagues as Brisson did.

The light blue triangle-marker line tracks Tricia Cotham's first tenure in the state house. For the early half of her time, her score matched her party, but in the later half, there is a subtle shift, with the party moving more liberal compared to her score. However, there wasn't a substantial difference between her score and the caucus, as compared to Brisson or Tine. 

Looking Forward

Until now, Cotham has straddled the line on many big-ticket political questions. The question remains whether Cotham's voting record will shift rightward to match her new party affiliation. 

With issues like abortion, education funding, the state budget, and LGBTQ+ issues likely coming to a vote soon, we may not have to wait long to measure measure the aftershocks of her party switch. 


Dr. Christopher Cooper is the Madison Distinguished Professor of Political Science and Public Affairs at Western Carolina University, where he serves as director of WCU's Public Policy Institute. He tweets at @chriscooperwcu.

Dr. Michael Bitzer holds the Leonard Chair of Political Science at Catawba College, where he is a professor of politics and history. He tweets at @BowTiePolitics