Michael McDonald
University of Florida
www.electproject.org



Closed vs. Open (Semi-closed) Primaries
Redistricting
Small donors
With Matthew Thornburg

Approach the issue from voters’ perspective,
comparing party registration in closed and
semi-closed states:
◦ Main theoretical insight: partisans in states
dominated by opposing party have greatest
incentive to register as an Independent in semiclosed states
Republicans – 2010 CCES
0.4
Probability Registering as Unaffiliated
0.35
0.3
0.25
0.2
Semiclosed
Closed
0.15
0.1
0.05
0
25
30
35
40
45
50
Obama Vote Share in State
55
60
65
70
Democrats – 2010 CCES
0.6
Probability Registering as Unaffiliated
0.5
0.4
0.3
Semiclosed
Closed
0.2
0.1
6E-16
25
-0.1
30
35
40
45
50
Obama Vote Share in State
55
60
65
70
With Micah Altman

Created award-winning open-source, webaccessible redistricting software
(www.DistrictBuilder.org) and deployed in
support of advocacy efforts and official
governmental redistricting.
◦ Thousands of users created hundreds of redistricting plans.
◦ Evaluate these plans on compactness, competitiveness,
partisan fairness, locality splits, voting-rights, etc.
Competitiveness
(Dem Maj. Between 45%-55%)
16
14
12
Florida
10
8
6
8
6
4
Virginia
2
0
12
10
8
6
4
2
0
Compactness
Ohio
Adopted Plan = ▲
4
Partisan Bias
(Dem Maj. Deviation from 50%)
2
0
Florida
-2
-4
-6
0
-1
Virginia
-2
-3
4
2
0
Ohio
-2
-4
-6
Compactness
Adopted Plan = ▲
With Tyler Culberson and Suzanne Robbins

Analyze internal FEC data to examine
patterns of aggregate small donor giving to
incumbents, challengers, and candidates in
open seats.

Using Bonica’s Candidate Ideology CFScores:
◦ On average, ideologically more extreme incumbents
raise $103,183 more than moderate incumbents.
◦ Challengers did not raise more money from their
own extremism or the extremism of their
incumbent opponent

Primaries
◦ May diminish polarization

Redistricting
◦ May diminish polarization

Small donors
◦ May increase polarization
Michael McDonald
University of Florida
www.electproject.org