[EM] Condorcet IRV Hybrid

[Forest Simmons]

Here's a Condorcet IRV Hybrid similar to Benham's version:

Use IRV to eliminate candidates until one of the remaining candidates
covers the other remaining candidates.

The rationale for this proposal is that a candidate who merely beats
(pairwise) the other remaining candidates may not be considered strong
enough for an exemption from elimination, but such a candidate has a
stronger case if she also beats every candidate that is beaten by any of
the remaining candidates.

What made me think of this version is that our DMC (Democratic Majority
Choice) proposal to Toby Nixon eliminated low approval candidates until
there was a beats all candidate among the remaining.  In my opinion the DMC
is much improved if you keep eliminating low approval candidates until one
of the remaining candidates covers the others: you tend to get higher up
the approval chain.  In this modified version of DMC if there is no
Condorcet candidate, then most of the time the highest approval Smith
candidate will win. In particular, if (as in a cycle of three) no member of
the Smith set covers any other member of the Smith set, then the highest
Approval Smith candidate wins.

The following observation about Condorcet IRV Hybrids has probably already
been made (but I have been gone for a while):

These hybrids have no good defense against burying.  For example

Sincere  ballots:

40  A>C
35  B>C
25  C>A

If the A faction decides to bury C, there is nothing the C faction can do
about it unilaterally. They have to depend on the willingness of the B
faction to elevate their compromise over favorite.

Forest
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