an excellent question.

to answer it, i think we have to first interrogate whether there have in fact been any actual identifiable cases of this sort of thing by republicans. i can't think of any.

i'm familiar with some rather sketchy allegations, such as the perrenial "misleading flier" which always seems to be "discovered" by a democrat in a majority black district prior to an election.

i'm also familiar with the documented instance a few years back when the dnc handbook distributed to pollwatchers instructed volunteers to invent instances of voting irregularities.

i'm also familiar with the raft of fairly penny-ante vote-fraud in, for instance, east st. louis, and with pay-per-registration schemes set up by progressive community orgs which have resulted in thousands of fraudulent registrations. all of these implicate democrats.

finally, i'm familiar with grand conspiracies about the evil republican octopus reversing national elections with the flick of a switch.

i think the reason that, as you put it, stories of democrat vote fraud are marked as benign incompetence while stories of republican vote fraud are marked as deliberate malignancy, is because the actual documented instances of democrat vote fraud - though telling of the character of democratics - are barely consequential, while the stories of republican vote fraud are concocted by democratics with the aim of portraying republicans as conniving and malign.

as a conservative fed up with the lucrative and corrosive industry of alleging that republicans controll the final tallies nationwide through manipulation of electronic voting machines, i would have loved to have pointed to chicago's adoption of sequoia systems and said something rediculous like, "a-hah! chicago's progressive mafia is using hugo chavez's machines to preserve their power!"

but working as an election judge in some precincts where i would have expected to see some funny business, i've witnessed none. i've seen a rocky implementation process of a new system.

cook county commissioner david orr, a north side progressive who, if i had to guess, probably voted obama, is an earnest public servant who has done much i think to make voting better in chicago. he's gained my trust.

chicago however remains a city riven with radical progressive cults, union thugs and democrat party machine crap, and so there's no end to what some student activist assigned to a polling place, for instance, is willing to do to undo "mere bougois democracy".