Republican presidential nominee, former U.S. President Donald Trump holds a campaign rally at Lancaster Airport on November 03, 2024 in Lititz. (Photo by Chip Somodevilla/Getty Images)
In light of the success that statewide Republican candidates had in 2024, some analysts hint that Pennsylvania is headed the way of Florida, a one-time swing state that has become reliably Republican.
The state’s Democratic partisan voter registration advantage has declined from 1.2 million to around 340,000 over  the last decade, and there have been geographic, demographic and social changes happening within each party. But did Trump really drive those changes? And do they represent a durable realignment in the state that advantages Republicans, making them the state’s dominant party?
Aligning changes in voter registration to a president’s term of office is the most logical way to understand the impact of presidential personalities and policies on state politics. The single largest period of partisan change this century took place during the second term of the Bush administration, when Democratic registration surged and Republican registration sank. Voters in the second term of the Bush administration were extraordinarily negative about Bush’s performance and it drastically changed the state’s partisan balance, giving Democrats a registration advantage of 1.2 million voters by the end of his term.
The single largest drop in Democratic partisan registration since 2000 took place during Biden’s term of office, which again corresponds to a period of relatively poor presidential ratings, even among Biden’s own partisans.
The greatest increase in Republican registration this century occurred during Trump’s first term, but the largest relative growth was among third-party registrants.
In fact, growth in unaffiliated and third-party registration outpaced growth for the major parties during every administration this century except during Bush’s second term. While both major parties had registration growth since 2000, third-parties had the most relative growth, rising from under 800,000 voters in 2000 to 1.4 million in 2024.
From a historical perspective, the Trump bump is more a bend than a bounce. Partisan registration shares may have converged a bit faster after 2016, but there is no pronounced jump in registration as has appeared at other periods in the state’s history. The most abrupt change in the state’s voter registration happened between 1932 and 1936, during Franklin Roosevelt’s first term. Roosevelt’s candidacy and presidency profoundly changed the state’s politics, finally making it possible for Democrats to compete in the state.
Other presidential eras have also produced noticeable breaks with past trends. The most pronounced changes took place in 1956 – 1960, 1972 – 1976, and 2004 – 2008, but none has come close to driving change like FDR’s New Deal. The partisan movements associated with the Trump era fall closer to the normal rates of change evident throughout recent history than to the largest disruptions of past eras, perhaps because Trump had no objectively obvious economic tailwinds to ride. Many people reported being worse off economically in 2024 than in the prior year, but objective measures of GDP did not show a recession. The sharpest swings in voter registration have usually coincided with sizable recessions.
Identifying critical elections that signal a break from past politics is hard to do in real time. Sometimes a critical election produces a sudden notable change that fades gradually, as happened during the New Deal Era. In other circumstances, the initial changes are small but ripple outward and grow over time. Some scholars believe this happened in the mid-to-late 1960s and played out into the emergence in the 1990s of sustainable Republican U.S. House majorities. The evidence from history suggests that the Trump era, while significant for many reasons, has not been outside the norms of historical partisan switching.  History also suggests the electoral ripple effects could play out for some time.
The changes in registration taking place during the past decade were mostly created by President Trump taking advantage of the changes already happening within the state’s electorate, including movement away from both major parties. The Trump-driven move in registrations does not yet give Republicans a durable advantage. The electoral implications of the state’s partisan shifts point to a near future that remains highly competitive because of a smaller registration advantage for Democrats and a rising share of unaffiliated voters.
Democrats had the opportunity in 2008 to create changes to the policy status quo that could have cemented their partisan advantages, but they failed. A similar opportunity now belongs to the Republicans, who enjoy not only Trump’s presence in the White House but also bicameral majorities in the House and Senate and a sympathetic Supreme Court.
Will Republicans be more successful than Obama-era Democrats were at creating a new policy coalition from an electorate longing for change? Their policies will matter more than the president’s personal popularity if they hope to build a sustainable and enduring advantage in future elections.
Berwood Yost is the director of the Franklin & Marshall College Poll