the blog of DC Drinking Liberally

October 10, 2007

DC for Democracy’s Instant-Runoff-Based Endorsement Vote

by

[I wrote this for the DC for Democracy site but thought I’d post it here too for other people who might be interested in the endorsement method as well as the levels of support of various candidates among one segment of the progressive grassroots in DC (plus I haven’t posted anything here for a while).]

On October 3, DC for Democracy endorsed Barack Obama in the Democratic presidential primary. It was the first time the group used a new procedure based on instant-runoff voting (IRV) that they adopted last month. Since both DC4D members and outsiders may be interested in seeing exactly how the result was arrived at, as well as how much support various candidates had, I thought I’d go through the details.

The bottom line is that Obama got 53 percent of the first-choice votes plus another 16 percent from second-choice votes, for a total of 69 percent support (which exceeds the two thirds required for endorsement), and Edwards came in second, with 49 percent support (split evenly between first-choice and second-choice votes). See below for colorful charts and perhaps more than you want to know about the vote.

After the 2006 DC primary, which featured council races with as many as 19 candidates, some DC4D members began to feel that our endorsement rules might need some revision. With a large field of candidates and each member able to vote for only one, it was unlikely that any candidate would reach the two-thirds threshold required for endorsement. To remedy that, we looked for a system that would allow members who believed more than one candidate met the criteria for endorsement to express that in their votes.

We started with IRV-based endorsement rules suggested by the Center for Voting and Democracy (aka FairVote) and after member input decided to limit voters to ranking no more than two candidates. The resulting procedure was adopted by the DC4D membership at the September meeting and now is included in the bylaws (PDF). Here’s the relevant bit, which seems more complicated than it is because it has to deal with fiddly details like resolving ties:

If there are more than two endorsement options, a modified instant-runoff vote is used to give voters the option of expressing support for more than one option. This will generally happen only for candidates, since other endorsements will be yes or no votes. Each voter may cast one vote for a candidate (or for “No Endorsement”) and then, if desired, cast a second-choice vote to be used if the preferred candidate is eliminated during the counting. Voters should not cast any votes for a candidate they would not
be willing to endorse. Votes are counted as follows:

  1. First-choice votes are totaled.
  2. If one candidate reaches two-thirds, the endorsement is made and the process is complete.
  3. If no candidate has reached two-thirds and two or more candidates remain, the candidate with the fewest votes is eliminated and those votes are transferred to the second-choice candidates marked on those ballots, if there are any. Ballots with no second-choice candidate, and ballots whose second-choice candidate has already been eliminated, are assigned to “No Endorsement” (a special “candidate” that is never eliminated). Go back to step (2).
  4. If only one candidate and “No Endorsement” remain, and the candidate has not reached two-thirds, then no endorsement is made and the process is complete.

Resolving ties: If a candidate must be eliminated during counting and candidates are tied for the fewest votes, then the candidate among them with the fewest votes in the previous round of voting is eliminated (and the round before that can be used as a further tiebreaker if necessary, and so on). If the candidates are tied in all earlier rounds as well, then all of them are eliminated.

There were 45 votes total, with 26 voters (58 percent) taking the opportunity to indicate a second choice. I’m representing votes as colored squares, with each candidate assigned a color. If there’s a second choice, the bottom half of the square is colored for that candidate. (Note that a second choice of “no endorsement” or the same candidate as the first choice — voting Edwards and Edwards, for example — is equivalent to making no second choice.) For example, a red square () indicates a vote for Biden only, while a square that is red on the top and green on the bottom () represents a vote for Biden as first choice and Edwards as second. The votes were distributed as follows:

1st 2nd
1 Biden ——
1 Biden Edwards
1 Clinton ——
1 Clinton Edwards
5 Edwards ——
1 Edwards Gravel
1 Edwards Kucinich
4 Edwards Obama
1 Kucinich Obama
     
1st 2nd
1 Kucinich Richardson
11 Obama ——
2 Obama Clinton
8 Obama Edwards
1 Obama Gravel
2 Obama Richardson
1 Richardson Edwards
2 Richardson Obama
1 No endorsement

Round 1. The first step is to assign each vote to the first-choice candidate. This produces a count of 24 for Obama; 11 for Edwards; 3 for Richardson; 2 each for Biden, Clinton, and Kucinich; 1 for no endorsement; and 0 for Dodd and Gravel (note that each vote is still represented by a square, as above):

With 45 votes, a candidate needs 30 (two thirds) to win the endorsement. Since no candidate has reached that, we move on to eliminate candidates and reassign votes until the threshold is reached or we’ve run out of candidates.

Round 2.This procedure features multiple rounds of counting, in which candidates are eliminated and votes reassigned, but there is only one round of voting — members fill out one ballot and that’s it. In this case, the second round of counting is trivial. Since Dodd and Gravel are tied for the fewest votes, both are eliminated. Since they have no votes, there are no votes to reassign, and the other candidates’ totals remain the same:

Round 3. For the third round, Biden, Clinton, and Kucinich are tied for the fewest votes, at 2. Since they were also tied in the previous round, all three are eliminated simultaneously, and their votes are reassigned as follows:

That gives us new totals of 25 for Obama, 13 for Edwards, 4 for Richardson, and 3 for no endorsement:

Round 4. For the fourth round, Richardson has the fewest votes, at 5, so he is eliminated. One of his votes comes from a ballot where he was the second choice, so there are no remaining candidates for it to go to and it goes to no endorsement. The remaining votes go to the voters’ second choices: 2 for Obama and 1 for Edwards. The totals are now 27 for Obama, 14 for Edwards, and 4 for no endorsement:

Round 5. Since no candidate has yet reached the 30-vote threshold, we continue to the fifth and final round of counting. After this round, we’ll be down to only one candidate, so if he doesn’t reach the threshold, there will be no endorsement. Edwards has the fewest votes, with 14, so he is eliminated and his votes reassigned:

That gives final totals of 31 for Obama and 14 for no endorsement:

Obama reaches the two-thirds threshold and is endorsed.

post a comment

You must be logged in to post a comment.

About

DCDL is a blog by Washington, DC-area members of Drinking Liberally. Opinions expressed are the writers’, not those of Drinking Liberally, which provides no funding or other support for this blog.

Upcoming Events

See information on the revived DC chapter (2012).

DCDL Member Blogs

DCDL Speaker Links

DC Links

Liberal (Mostly) Blogs

Liberal Groups

Internal Links

Contact

keith@dcdl.org

Drinking Liberally

Recent Comments

Recent Posts

Categories

Search Blog

Archives

Geekery

46 queries. 0.662 seconds