Why do liberals protect duplicate voter registrations?

A common voice of disdain for the Evergreen Freedom Foundation’s recommended policy to require an update (see here) of all Washington’s voter registrations is that the objective is to “get a Republican majority by default.”

This objection to the policy I have seen numerous times in editorials, letters to the editor and liberal blogs.

Do liberal-minded opponents then concede that if it weren’t for all of the bad registrations in the statewide voter database their Democratic party would not fair too well in elections?

Liberals and conservatives alike surely agree that the database is full of illegitimate registrations (the dead, duplicate and dubious registrations).

So, is this the general consensus amongst Democrats? My own understanding of this argument is left wanting.

If there are liberal readers perusing this conservative blog (for kicks, we’ll say) then refute this by all means.