By Christopher Cooper and Michael Bitzer
The impeachment of Donald Trump 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 could have taken place eight hours from the eye of the storm Trump. On April 5, 2023, Tricia Cotham, a Democratic legislator in the North Carolina House of Representatives, announced that she would be changing political parties. Elected as a Democrat, Cotham is now a Republican.
Cotham’s measure essentially rendered Governor Cooper’s veto ineffective. Republicans now have majority control of both houses 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 changes like Cotham’s are rare, they are not unheard of. According to the political scientist Boris Schor, 427 state legislators changed political parties between 1989 and 2020. Most of these changes took place in the southern United States, with the vast majority leaving the Democratic Party for the Republican Party. This fits in with the larger story of partisan change in the American South.
Of course, Cotham’s change is significant not just because she changed, but because her change changed the North Carolina House of Representatives from Republican control to Republican majority control. While most switches don’t have such wide reverbs, some do. In 2002, Georgia state representatives Lee, Cheek, and Bowen switched from the Democratic Party to the Republican Party, shifting control of the house from the Democratic to the Republican Party, a status that has held ever since. A similar story unfolded in Mississippi when state senator James Walley switched from the Democratic Party to the Republican Party, leaving the chamber deadlocked.
Which brings us to North Carolina.
What about party-switchers in the old upstate?
Several members of the North Carolina General Assembly have changed party affiliations since 1995. In particular, Michael Decker, a Republican from Forsyth County, created a political storm when he switched to Democrat. In doing so, Decker flipped a 61-59 Republican majority in the state house in the 2003 legislative session to a 60-60 bipartisan tie, with a later deal allowing Democratic leader Jim Black and Republican Jim Morgan to serve as ‘co-speakers’ for the state house.
Ultimately, this change became the basis for criminal investigations, one of which culminated in Decker’s guilty plea to accepting an illegal contribution of $50,000 from Jim Black, in exchange for switching parties and supporting Black, and Black’s subsequent conviction on corruption charges. The bribery, as veterans of North Carolina politics know, took place in the bathroom of a Salisbury, North Carolina IHOP restaurant (sometimes truth is stranger than fiction).
Most recently, state Rep. Paul Tine switched from a Democrat to an unaffiliated legislator in 2015. Critically, after his switch, he rejoined the Republican majority. In making his decision, Tine said he “wanted to be in the moderate Democratic fold, but felt the party was veering too far to the left for him.” After his trade, he decided not to run for re-election.
Two years later, state representative Bill Brisson also switched parties, moving from the Democratic to the Republican side of the aisle. Brisson explained that “my entire district is rural, and many of my constituents are. I’ve had a lot of pressure from my constituents in recent years to change. I don’t have much in common with the Democratic Party right now because they’ve become so liberal “.
What Research Tells Us About Party Switchers
Political science research on party switching offers some clues as to what constitutes a “normal” party switch. There is considerable evidence that many who switch parties take action because they have a progressive political ambition (they want to run for higher office). This, of course, makes sense. If you find yourself in tune with the people who currently represent you, but out of step with the people who might vote for you for the next step in the last political step, you can switch parties (see Antoine Yoshinaka’s Crossing the Aisle for the best book). -long treatment of this idea).
Not surprisingly, some legislators switch parties after redistricting. If a legislator’s old district doesn’t look like her new district, she may switch parties to increase her chances of re-election. Others change after a new party takes control of the camera. The logic here is simple: if you want to pass a policy, you better be in the majority party.
Then there is the question of ideology. Do legislators switch parties not out of progressive ambition or re-election motivation, but because they are ideologically out of step with their parties? There is some evidence of that motivation, particularly in the American South, where once common conservative Democrats are now as common as four-leaf clovers at the North Pole. These conservative Democrats may choose to leave the party for a home where they find more ideological allies.
So how does Cotham’s switch fit in with these explanations?
How does all this square with the Cotham change?
Two political scientists, Bors Shor and Nolan McCarty, have studied the ideological mapping of US state legislatures. In doing so, they created a database of roll call votes in the nation’s state chambers and assemblies to locate individual members, and their respective parties and chambers, along an ideological spectrum, thus creating a comparative score for each. member and chamber/party. .
Below, you can see the ideology scores for 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 placed in containers. The solid line that looks like two hills is a summary of the boxes. As you can see, the North Carolina General Assembly consists mostly of two normal curves with some legislators at the ends and some in the middle. The ideology expressed by Tricia Cotham is represented by the vertical dotted line.
The bottom line here is that Tricia Cotham’s past voting record is toward the moderate end of the Democratic Party, but, at least to this point, she is not “out of step” with her fellow Democrats.

What will happen now?
The above figure, while helpful, ignores changes over time. The figure below shows the scores for house parties in the state of North Carolina between 1995 and 2018. Once again, the positive scores in the and The axis indicates a more conservative ideology, while negative scores indicate a more liberal ideology. Based on the two solid lines (red for the Republican caucus, blue for the Democratic caucus), prior to 2008 the parties were fairly consistent in their line, but after 2008 the parties have moved further away from each other to the extremes. ideological. This is a likely sign of the ‘classification’ that political parties and their members have suffered in recent years.
Data from Schor (2020); Graphic by Michael Bitzer. |
We also mapped two of those who switched parties since 1995, Bill Brisson and Paul Tine. In the case of Brisson (the dark red line of the round marker), he was obviously a very conservative Democrat, in the fact that he was in positive conservative territory from 2007 to 2017, and when he switched parties, he aligned himself even more closely with his new fellow Republicans.
For Tine (depicted in the squared purple line), his first two years in the state house saw him score negative, but there was distance between him and his fellow Democrats. With his non-affiliation and caucus with the Republican Party, Tine became more conservative, but not as close to his new colleagues as Brisson did.
The light blue triangle marker line traces Tricia Cotham’s first term in the state house. During the first half of her time, her score matched her match, but in the second half, there’s a subtle shift, with the match moving more liberally compared to her score. However, there was no substantial difference between her score and that of the caucus, compared to Brisson or Tine.
Thinking in the future
So far, Cotham has crossed the line on many important political issues. The question remains whether Cotham’s voting record will shift to the right to match his new party affiliation.
With issues like abortion, education funding, the state budget, and LGBTQ+ issues likely coming up for a vote soon, we may not have long to wait to gauge the repercussions of his party switch.
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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 Institute for Public Policy. he tweets on @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 on @BowTiePolitics.