Table 1: Voting and Party Registration for the 2004 Presidential Elections in Florida.

Sources: http://enight.dos.state.fl.us/ (Nov 5 2004), http://election.dos.state.fl.us/voterreg/vrArchive/2004voterreg.shtml#04gen

County	Voting Machine	Votes (100% reporting)			Party Registration (Oct 4 2004)			%Votes Difference	%Registration Difference
		Republican	Democratic	Total	Republican	Democratic	Total
Alachua	Op-Scan-Precinct	47615	62348	111022	39605	71948	142358	-13.3	-22.7
Baker	Op-Scan-Precinct	7738	2180	9955	3126	8926	12887	55.8	-45.0
Bay	Op-Scan-Precinct	53388	21058	74998	44751	39707	101315	43.1	5.0
Bradford	Op-Scan-Precinct	7553	3244	10851	4168	9039	14721	39.7	-33.1
Brevard	Op-Scan-Precinct	152838	110153	265075	151535	123578	338195	16.1	8.3
Broward	E-Touchscreen	243118	451521	702949	283736	533976	1058069	-29.6	-23.7
Calhoun	Op-Scan-Precinct	3780	2116	5961	993	6879	8350	27.9	-70.5
Charlotte	E-Touchscreen	44402	34227	79730	51110	36306	113808	12.8	13.0
Citrus	Op-Scan-Precinct	39498	29274	69462	37653	35340	90780	14.7	2.5
Clay	Op-Scan-Precinct	61881	18905	81230	60192	27282	106464	52.9	30.9
Collier	E-Touchscreen	83485	43713	128352	89559	41082	168673	31.0	28.7
Columbia	Op-Scan-Precinct	16753	8029	24984	10737	19374	34282	34.9	-25.2
DeSoto	Op-Scan-Precinct	5512	3910	9495	3787	8838	14901	16.9	-33.9
Dixie	Op-Scan-Precinct	4433	1959	6440	1454	7495	9676	38.4	-62.4
Duval	Op-Scan-Precinct	219251	158121	379614	190111	238264	515202	16.1	-9.3
Escambia	Op-Scan-Precinct	93367	48243	142990	83165	77250	189833	31.6	3.1
Flagler	Op-Scan-Precinct	19632	18574	38475	19179	17940	47068	2.7	2.6
Franklin	Op-Scan-Precinct	3472	2400	5930	1212	5893	7620	18.1	-61.4
Gadsden	Op-Scan-Precinct	6253	14629	20984	3012	22280	26884	-39.9	-71.7
Gilchrist	Op-Scan-Precinct	4934	2016	7012	2750	5295	9035	41.6	-28.2
Glades	Op-Scan-Precinct	2443	1718	4188	1479	3867	5963	17.3	-40.0
Gulf	Op-Scan-Precinct	4794	2398	7256	2557	6464	9627	33.0	-40.6
Hamilton	Op-Scan-Precinct	2792	2260	5079	1140	6029	7645	10.5	-64.0
Hardee	Op-Scan-Precinct	5047	2148	7246	2779	6630	10399	40.0	-37.0
Hendry	Op-Scan-Precinct	5756	3960	9774	5279	9688	17144	18.4	-25.7
Hernando	Op-Scan-Precinct	40137	35006	75832	45266	42554	109656	6.8	2.5
Highlands	Op-Scan-Precinct	25874	15346	41491	26752	23939	60176	25.4	4.7
Hillsborough	E-Touchscreen	244606	213413	461520	217766	258882	621201	6.8	-6.6
Holmes	Op-Scan-Precinct	6410	1810	8298	2344	7988	10982	55.4	-51.4
Indian River	E-Touchscreen	36869	23932	61321	41866	24515	81643	21.1	21.3
Jackson	Op-Scan-Precinct	12115	7552	19797	5962	19411	27138	23.0	-49.6
Jefferson	Op-Scan-Precinct	3298	4134	7477	1929	6726	9300	-11.2	-51.6
Lafayette	Op-Scan-Precinct	2460	845	3325	570	3570	4309	48.6	-69.6
Lake	E-Touchscreen	74382	48216	123938	76387	55258	161269	21.1	13.1
Lee	E-Touchscreen	144414	94365	241433	144948	90716	304937	20.7	17.8
Leon	Op-Scan-Precinct	51594	83830	136314	45578	97672	171182	-23.6	-30.4
Levy	Op-Scan-Precinct	10408	6073	16649	6241	13503	22617	26.0	-32.1
Liberty	Op-Scan-Precinct	1927	1070	3021	320	3597	4075	28.4	-80.4
Madison	Op-Scan-Precinct	4196	4048	8307	1695	9042	11371	1.8	-64.6
Manatee	Op-Scan-Precinct	81272	61228	143539	84804	63305	191635	14.0	11.2
Marion	Op-Scan-Precinct	81267	57255	139644	79572	73168	184257	17.2	3.5
Martin	E-Touchscreen	41350	30197	72430	51869	27203	98857	15.4	25.0
Miami-Dade	E-Touchscreen	358613	406099	768553	368334	453631	1058801	-6.2	-8.1
Monroe	Op-Scan-Precinct	19462	19649	39525	19874	18563	51377	-.5	2.6
Nassau	E-Touchscreen	23732	8545	32664	20300	15218	41353	46.5	12.3
Okaloosa	Op-Scan-Precinct	69654	19358	89707	72885	31526	127455	56.1	32.4
Okeechobee	Op-Scan-Precinct	6987	5151	12197	5537	10891	18627	15.1	-28.7
Orange	Op-Scan-Precinct	192390	193217	387752	186614	213702	531774	-.2	-5.1
Osceola	Op-Scan-Precinct	43108	38617	82178	42462	52064	129487	5.5	-7.4
Palm Beach	E-Touchscreen	211894	327698	542835	233495	329232	729575	-21.3	-13.1
Pasco	E-Touchscreen	103198	84731	190866	106649	99272	265974	9.7	2.8
Pinellas	E-Touchscreen	225627	225367	455203	231652	223544	590989	.1	1.4
Polk	Op-Scan-Precinct	123532	85983	210777	115211	125870	295742	17.8	-3.6
Putnam	Op-Scan-Precinct	18305	12409	30964	12728	26184	45344	19.0	-29.7
Santa Rosa	Op-Scan-Precinct	51988	14637	67213	53853	27083	96359	55.6	27.8
Sarasota	E-Touchscreen	104630	88382	195530	115317	74986	240592	8.3	16.8
Seminole	Op-Scan-Precinct	108126	76938	186115	107613	77964	241230	16.8	12.3
St. Johns	Op-Scan-Precinct	59178	26389	86262	58436	31051	109635	38.0	25.0
St. Lucie	Op-Scan-Precinct	47519	51760	99913	50436	57128	137951	-4.2	-4.9
Sumter	E-Touchscreen	19795	11584	31837	17631	16553	40523	25.8	2.7
Suwannee	Op-Scan-Precinct	11153	4521	15801	5885	13941	21930	42.0	-36.7
Taylor	Op-Scan-Precinct	5466	3049	8580	2170	8679	11481	28.2	-56.7
Union	Op-Scan-Precinct	3396	1251	4675	1291	5331	7063	45.9	-57.2
Volusia	Op-Scan-Precinct	111544	115319	228358	111372	126405	309930	-1.7	-4.9
Wakulla	Op-Scan-Precinct	6777	4896	11763	3730	10293	15396	16.0	-42.6
Walton	Op-Scan-Precinct	17553	6213	23974	16413	12051	32777	47.3	13.3
Washington	Op-Scan-Precinct	7368	2912	10365	3666	9668	14421	43.0	-41.6

%Votes Difference = (Republican Votes – Democratic Votes) / Total Votes * 100%

%Party Registration Difference = (Republican Registration – Democratic Registration) / Total Registration * 100%

Table 2: Pearson's Correlation Between %Party Registration Difference and %Votes Difference.

Voting Machine	Number of Counties	Correlation	Statistical Significance
E-Touchscreen	15	0.78	p < 0.001
Op-Scan-Precinct	52	0.09	n.s.
Total	67	0.05	n.s.

Table 2 shows that there is a strong relationship between party registration and voting if the E-Touchscreen voting machine is used, but not if the Op-Scan voting machine is used. If all counties are taken together, then there is also no relationship between party registration and voting.

Figure 1: A scattergram of the %Registration Difference and the %Voting Difference, split by the Voting Machine that was used.

If there is a strong relation between voting and registration, then we expect most data points in the right-top (Republican Registration and Voting) and the left-bottom (Democratic Registration and Voting) quadrants. This is the case for the E-Touchscreen voting machines. If a voting machine produces random errors, then we expect data points in the left-top (Democratic Registration and Republican Voting) and the right bottom (Republican Registration and Democratic Voting) quadrants. We see a lot of data points in the left-top quadrant, but not in the right-bottom quadrant. This seems to suggest a biased error towards Republican vote counting in counties with strong Democratic Party Registration.

There is an issue of county size. If we split the counties in counties larger or smaller than 100,000 registered voters, we get:

Figure 2: A scattergram of the %Registration Difference and the %Voting Difference, split by the Voting Machine that was used for large counties.

Figure 2 shows that there is a similar relationship between Party Registration and Voting, but the Op-Scan voting machines register about 6% larger Republican - Democrat difference than the E-Touchscreen voting machines. This is statistically significant (p < 0.01).

Figure 3: A scattergram of the %Registration Difference and the %Voting Difference, split by the Voting Machine that was used for small counties.

Figure 3 shows that there is no relationship between Party registration and Voting for the smaller counties. There are too few E-Touchscreen counties to say anything about the difference between the Voting machines.