Breaking Down Pennsylvania's Voter Registration Data

A number of news stories have focused on the fact that "46,000" (it's actually more than 49,000, as of March 7) Pennsylvania Democrats switched their voter registration to Republican, and speculated that's a "Trump effect."

Now 49,000 switches is a huge number, larger than past years, and that may be the “Trump effect”—though if it is, that runs against the narrative of “racist Republicans” supporting Trump, when it's Democrats who like Trump’s big government, xenophobic policies.

But it may also be the “Wolf effect,” or the “Obama effect,” or simply presidential election enthusiasm. It could also be folks switching to oppose Trump.

Most likely (this is my hypothesis), it’s the fact this will likely be the first time in decades Pennsylvania’s primary will help determine the GOP nominee.

But the fact is this number doesn't represent some mass movement or a resurgence of the Republican party in Pennsylvania.

1) Conversions from Republican to Democrat are also up. More than 25,000 Republicans and almost 32,000 "other" switch their registration to Democrat.

The 25,000 Republicans who switched in the first 3 months are also  higher than the total in 2013, 2014, or 2015. Moreover, Republicans usually have an advantage in party shifts, though Democrats have outpaced Republicans in getting independent voters to switch their party registration.

Party to Party Changes
	R to D	Other to D	D to R	Other to R	Net R Gain
2008 to 2012	78,224	55,216	125,215	47,054	38,829
2013	16,921	7,028	12,454	8,632	-2,863
2014	16,559	11,655	19,903	8,225	-86
2015	17,864	18,797	29,792	15,884	9,015
2016	25,390	31,678	49,856	24,972	17,760
Total	154,958	124,374	237,220	104,767	62,655

2) This doesn’t approach the wave of 2008. In the year before the 2008 primary (with the Obama wave and the close Obama-Clinton primary race), Democrats gained 328,000 registered voters, while Republicans lost 73,000—a net swing of 401,000. 

Over the past 10 months, Republicans have gained ground on Democrats, but only by 34,000 on Democrats.

Total Registered Voters in Pennsylvania
	Dems	GOP	Dem Advantage
May 2007	3,872,018	3,259,243	612,775
2008 Primary	4,200,109	3,186,057	1,014,052
Change	328,091	-73,186	401,277
May 2015	3,963,864	2,964,437	999,427
March 2016	3,996,333	3,031,114	965,219
Change	32,469	66,677	-34,208

3) Democrats continue to lead in new party registration. Democrats have had 6,000 more newly registered voters than Republicans, an have out-gained Republicans in new registration every year. While the first three months of 2016 are an exception, new voter registrations matters more than party-to-party shifts. Since 2008, Republicans are a +63,000 in party shifts, but Democrats are a +219,000 in new voter registration.

New Voter Registration
	D	R	Other	Net D-R
2008-09	84,527	53,786	47,018	30,741
2010	77,165	59,852	50,108	17,313
2011	77,562	60,605	45,858	16,957
2012	211,025	123,478	118,408	87,547
2013	69,808	46,842	47,951	22,966
2014	75,349	56,411	56,604	18,938
2015	89,310	70,487	53,082	18,823
2016	34,967	28,908	15,090	6,059
Total	719,713	500,369	434,119	219,344