On the other hand, under the present system the governor of, say, Florida can tilt the election by reducing/increasing the number of voting places in strategic locations.
Really??? That's not handled at the county level? It sure is in Missouri (http://www.moga.mo.gov/mostatutes/chaptersIndex/ChaptIndex11...), and I've never heard of it being done at the state level before---that would seem to be prima facie evidence of a discriminatory voting system---but maybe my education in this is lacking.