The state and national media are full of stories about the 2022 Pennsylvania primary election even though it won’t happen for more than a year.[i] Just a few weeks ago, the national news organization Politico published an in-depth profile about Pennsylvania Lt. Governor John Fetterman’s pursuit of the Democratic nomination for the US Senate [ii], which was preceded by similar reporting and profiles in other outlets.

This interest makes sense since the state’s US Senate seat will be pivotal in determining which party controls the Senate. Heightened media interest also makes sense since no incumbent is running; the state has had only three open-seat US Senate races since 1970 and this is the first open-seat race in Pennsylvania since 1991.[iii]

The interest in this race goes beyond the media–it is already drawing a large field of interested candidates, which is not unusual for open-seat races. Since 1970, the largest field of Republicans to run in a US Senate primary was eight in 1980 and six in 1976, both open-seat races. The largest field of Democrats to run for US Senate was eight in 1980 and six in 2000. The 1980 US Senate race, an open seat created by Senator Richard Schweiker’s retirement, had the largest primary field in recent history, with 16 total candidates. The 2000 Democratic primary, though not an open seat, attracted a lot of interest because it was Senator Santorum’s first re-election race.

Multi-candidate Senate races tend to produce plurality, not majority, winners. The winning candidate’s vote share for the Republican victor in 1980, Arlen Specter, was 36.4% and it was only 37.8% for John Heinz in 1976. The Democratic victor in 1980, Pete Flaherty, did achieve a majority vote share (53.3%), but Ron Klink, the victor in the 2000 race, won only 40.7% of the vote.

The circumstances and implications of the US Senate race are notable, but the fact that the state’s voters are also choosing their gubernatorial candidates makes the 2022 primaries historically unique. Since 1968, when Pennsylvania’s constitution was changed to allow governors to serve two terms, the state has never had open-seat races for governor and US Senate in the same election cycle.

Since 1970, the largest field of Republicans in a gubernatorial primary was six in 1978 and five in 1994. The largest field of Democratic gubernatorial candidates was seven in 1994 and six in 1970. As is true in the Senate primaries, multi-candidate races in gubernatorial primaries also tend to produce winners who capture less than 50% of the vote. The winning candidate’s vote share for the Republican gubernatorial primary in 1978, Dick Thornburgh, was 34.3% and in 1994 Tom Ridge received 34.6% of the vote. The Democratic gubernatorial winner’s share was 31.2% in 1994 for Mark Singel and was 57.6% for Milton Shapp in 1970. The 1994 gubernatorial race, an open seat to replace term-limited Governor Robert Casey, drew the most candidates (12 from both parties) in the modern era.

The unique circumstance of having two high-profile open-seat races guarantees that a large field of candidates will be running for office in the 2022 primary elections, and also suggests that the victorious candidates will win their primaries with less than 50% of the vote. This creates the opportunity for a candidate with a well-executed regional strategy to succeed.

Primary election turnout in Pennsylvania tends to be relatively low, averaging 28 percent of registered Republicans and 29 percent of registered Democrats in even numbered years. The highest Democratic primary turnout since 2000 was the 2008 Presidential primary between Barack Obama and Hillary Clinton; the 2016 and 2020 Presidential primaries also had turnout above 40 percent of registered voters. The highest level of Republican primary turnout was in the 2016 Presidential primary. Figure 1 shows the turnout among registered voters in both parties.

The ebb and flow of voter turnout underlines the effect of electoral competition on voter participation. The 2002 Democratic primary featured a contest between Ed Rendell and Bob Casey for governor and the 2010 Republican primary featured a gubernatorial contest between Tom Corbett and Sam Rohrer. The anomaly in this typical pattern is the high turnout 2004 Republican Senate primary that pitted Republican incumbent Arlen Specter against challenger Pat Toomey, a race that Specter narrowly won.

Besides the effect that competition has on voter turnout for both parties, the most interesting feature of primary elections over the past two decades is the sizable change in where the democratic electorate lives. Democratic primary voters are increasingly represented by voters living in and around Philadelphia and are less represented by those in the southwest (see Figure 2).

This geographic change in representation is stark. In 2000, two in five (38%) primary voters were from southwestern Pennsylvania and one in four (27%) was from the southeast. By the 2020 election those numbers had flipped: only one in five (22%) Democratic primary voters was from the southwest and nearly half (44%) were from the southeast. Republican turnout did not show any sustained geographic trend over the same time period.

These changes in primary turnout reflect the geographic changes that have taken place in the state’s voter registration rolls.[iv] Since 2000, the state’s largest counties, mostly in the southeast, were more likely to increase their shares of registered Democrats, and the smaller counties have almost invariably fewer registered Democrats. The Democratic registration growth in the southeast and decline in the southwest mirrors the change in Democratic primary representation over the past two decades. The interesting questions that come from this change are whether and how a Democrat’s prospects in a general election are affected by the predominance of urban and suburban voters in primary elections. Simply put, are such candidates well positioned to win with a statewide electorate?

Pennsylvania has held primary elections for more than a century and in that time primaries have been much more crowded when no incumbent was running for re-election.[v] Because 2022 will have open-seat primaries for both Senate and Governor, 2022 is likely to produce an avalanche of candidates. We should expect five or more candidates in each party’s primary when the final ballots are counted. [vi]

We might also expect that the winners of these primary races will get elected without receiving a majority of the votes cast, which increases the chances that a candidate will pursue a regional electoral strategy.

What is a near certainty, though, is that Pennsylvania is going to be the center of America’s political universe in 2022, drawing large amounts of money and attention. In the end, this competition should create higher than normal primary voter turnout for both parties, but will that turnout be anywhere close to the turnout seen in recent presidential primaries? Despite the interest this primary is generating, it would be a surprise if partisan turnout reached 40 percent.

[iii] The 1991 race was a special election to fill Senator John Heinz’s seat that saw Harris Wofford defeat former Republican governor and heavily favored Dick Thornburgh

[vi] Although in April of 2021 there were already at least four declared candidates for each party for the Senate race, it is probable that some of these declared candidates will withdraw from the race prior to the primary.