I don't really know how Clark would have done, but I agree that this doesn't seem to be a fair fight when the republican presidential race is already decided. Although, the results from Lane don't seem to back up the idea that voting is reduced by Republicans

           REGISTERED VOTERS - Democratic  .  .  .   103,496   46.89%
           REGISTERED VOTERS - Republican  .  .  .    58,800   26.64%
           BALLOTS CAST - Democratic .  .  .  .  .    54,995   59.32%
           BALLOTS CAST - Republican .  .  .  .  .    27,104   29.24%

At first I thought the 29.24% Republican vote was out of Republican voters, but it is out of all voters. So Dems voted at a higher rate and Reps did too (just not as much). Turns out nonpartisan voters didn't vote:

REGISTERED VOTERS - Nonpartisan .  .  .    47,007

BALLOTS CAST - Nonpartisan.  .  .  .  .     7,468 

Would the nonpartisans have voted for Clark? Do they normally not vote? Are these auto-enrolled voters?