The Lower House election Sunday fell about a year and nine months after the Supreme Court ruled that the preceding campaign, in August 2009, was held "in a state of unconstitutionality" because of the wide disparity in the weight of votes between electoral districts.
On Monday, two groups of lawyers filed lawsuits arguing that this year's race was unconstitutional because numerous districts with big populations are represented by too few Diet seats, while several districts with relatively small populations have too many representatives.
These lawsuits could be the last straw and the Supreme Court could finally move to void the existing single-district system by issuing a categorical "unconstitutional" decision — a ruling the top court has issued twice in the past on the multiconstituency system in the 1970s and '80s, even though it still fell short of invalidating the election results.