A group linked to the Service Employees International Union might be involved in massive voter registration fraud in Arizona and Colorado. From Russell Pearce (link):

There has been an accusation that 65% of 5000 voter registration forms, submitted by Mi Familia Vota and One Vote Arizona, in Yuma County on the last day of filling are invalid due to the registrant not being a citizen, wrong/invalid address, false signature, etc. I also understand that these 2 groups have signed up 20,000 states wide and they have requested that 45,000 be put on the permanent early ballot. If 65% of these last minute registration forms in Yuma are invalid, which may be more as they are still checking the rest, then what is the percentages of invalid in Maricopa, Pima and other counties...

Yesterday a Colorado judge threw out 6000 bogus voter registration forms submitted by the same SEIU off shoot Mi Familia Vota here in Arizona...

A big word of caution: the person making the 65% claim is an anonymous source of r/w blogger "Publius Pundit" (link), and this story is being spread by Gateway Pundit (link) at Andrew Breitbart's site (link). The Colorado story was reported in their local media, but the Arizona story has yet to be confirmed. At the least, Mi Familia Vota does appear to have close ties to the SEIU.

UPDATE: It's a good thing I added the "big word of caution". Arizona Secretary of State Ken Bennett has issued a press release "set[ting] the record straight on voter-registration fraud/Office watching issue closely, but confident that Internet rumors are without merit " (link) which includes:

Rumor: Activist groups Mi Familia Vota and One Vote Arizona filed 3,000 voter-registration forms with Yuma County in recent days.

Reality: Arizona's voter-registration deadline for the General Election passed on Oct. 4. Last week, groups like Mi Familia Vota did submit in Yuma County a few thousand applications for the state's Permanent Early Voter List, which qualifies voters to receive an early ballot. About 45% of those requests were rejected, in most cases because the applicant was already on the early-ballot list. No voters will receive more than one ballot. Oct. 22 was the deadline to request an early ballot for the General Election.

Rumor: As much as 65% of the last-minute voter-registration forms submitted by Mi Familia Vota and One Vote Arizona were deemed invalid by Yuma County .

Reality: In the 10 days leading up to the Oct. 4 registration deadline, Yuma County received 822 applications for voter registration. Of those, 84 were rejected.

Rumor: Other counties across Arizona , including Maricopa and Pima, have also been the target in recent weeks of systematic voter-registration fraud by Mi Familia Vota, One Vote Arizona and other groups.

Reality: No elections officials in Arizona 's 15 counties are reporting an inordinate number of invalid registration forms, nor a coordinated attempt to circumvent the state's voter-registration laws.

Between the end of July and Oct. 4, the deadlines to register for the Primary and General Elections, Pima County processed 29,192 valid registration forms. An additional 762 were rejected because they were incomplete or failed to prove citizenship. The bulk of the rejected forms were submitted by University of Arizona students who failed to include all necessary information, including a driver's license number and signature. Mi Familia Vota submitted just over 100 registration forms in Pima County, and a handful was deemed invalid.

During the 10 days leading up to the Oct. 4 deadline, Maricopa County received 6,129 voter-registration forms from Mi Familia Vota and similar groups. Of those forms, 1,417 were rejected.

Pearce has provided an update (link); he admits he might have relied on some bogus information, but he still thinks there's something there. It doesn't appear that "Publius Pundit" or BigGovernment have posted updates.