The highly respected Brennan Center for Justice at New York University's School of Law, has a comprehensive, well researched and documented white paper by Justin Levitt on recent allegations of voter fraud allegedly occurring in Wisconsin and other states within the last eight years, entitled, "The Truth About Voter Fraud."

Once you read it, your eyes will be opened to the sham that is being perpetrated upon the U.S. voters. In fact, one could easily argue that the widespread rumors of voter fraud exist to confuse the populace and further deepen the cynicism of our electoral process. These efforts may also serve a larger agenda to keep real voting reform off the table, that is, extending the time people are allowed to cast votes; make it LESS burdensome for people to vote in the first place; and acts by political campaigns to buy votes, among many others.

A nonpartisan task force is being created to investigate the claims of voter fraud in Wisconsin. They could save a lot of time and money by simply reading this excellent report RIGHT NOW.

Since the 2004 election, there have been persistent, unsubstantiated rumors of voter fraud in Wisconsin, and Milwaukee in particular. Wisconsin Attorney General J. B. Van Hollen, who is also co-chairman of the Wisconsin campaign of presidential candidate John McCain, is knowingly using these unsubstantiated rumors in his efforts to suppress legitimate votes in Wisconsin this November.

As reported elsewhere, Van Hollen has a serious conflict of interest here.
This attack on Wisconsin voters by the GOP and Wisconsin's own attorney general is also part of their support to enable the Real ID act, a costly, burdensome requirement that will do nothing to clean up state elections. From the report:

The 2004 election was hotly contested in Wisconsin, and various irregularities led to inflated claims of widespread fraud. At the same time, Wisconsin citizens were debating a proposal to require restrictive identification of each voter at the polls, and the fraud claims were used to support the call for ID. We examined each of the allegations of fraud by individual voters—the only sort that ID could possibly address—to uncover the truth behind the assertions ... these claims of voter fraud are frequently used to justify policies that do not solve the alleged wrongs, but that could well disenfranchise legitimate voters. Overly restrictive identification requirements for voters at the polls — which address a sort of voter fraud more rare than death by lightning — is only the most prominent example.

Here are the bogus allegations of voter fraud in Wisconsin, with clear and concise research that exposes the truth. I encourage you to read the entire report.

Invalid addresses: Based on an attempt to match voter roll entries to the U.S. Postal Service’s database of street addresses, 37,180 people in Milwaukee were alleged to have registered from invalid addresses. Of these, 31,500 listed accurate street addresses, but had problems with an apartment number. Further review of the remaining allegedly invalid addresses revealed cases in which the list was corrupted; digits were dropped on some entries, making otherwise valid addresses appear fictitious. This review also showed typos turning valid addresses into invalid ones. Though reporters following up on the story could not locate 68 listed addresses, at least 400 addresses were affirmatively proven to be valid. The bipartisan Milwaukee Election Commission ultimately threw out a challenge lodged to 5,619 of the entries, citing insufficient evidence that the registrations were invalid. Still, poll workers were specifically instructed to ask challenged voters for proof of residency, so every voter on the list of 5,619 should have been asked for proof of proper residency.

1,242 Milwaukee votes were cast from allegedly invalid addresses, based on another computerized match; this match paired voter rolls with U.S. Postal Service and City of Milwaukee property lists, with spot checks of 40 specific addresses.191 A sample of 300 of the entries showed that about 20% of the invalid addresses were attributed to data entry errors (e.g., “3130 S. 15th Place” became “3130 S. 15th St.,” and “S. 68th St.” became “S. 63rd St.”). At least two other addresses ostensibly deemed business locations were found to be valid residences after an individual spot-check. Furthermore, 75% of these votes were from Election Day registrants, who were required to show proof of residence at the polls.

Faulty registration cards: In Milwaukee, 10,921 voter registration cards from Election Day voters were allegedly unable to be processed. This allegation turned out to be an error; in fact, 1,305 Election Day registration cards from Milwaukee could not be processed. 548 of these listed no address, and 48 cards listed no name, but voters had to show both proof of name and proof of residence to register on Election Day. 236 cards had missing or incomplete dates of birth, 28 had no signature, 141 listed addresses outside of the city limits, and 23 were deemed illegible. 155 cards were not processed because they had not been given a voter number by the city. It is unclear why the remaining 126 cards could not be processed.
3,600 address verification cards mailed using information entered from these Election Day registrations were returned as allegedly undeliverable. We are not aware of any further public investigation of these cards.
2,200 address verification cards from outside of Milwaukee, mailed using information entered from Election Day registrations, were also returned as allegedly undeliverable.196 313 of these were from Racine: 207 were returned because the voter moved after the election, and at least 24 addresses were entered incorrectly by election workers.Of the 1,887 returned address verifications of Election Day registrations from elsewhere around the state, 1,198 were returned because the voter moved after the election or was temporarily absent when the card arrived; 610 showed a valid address but the individual could not be found there; 36 had an incorrect street number; 2 had an incorrect street name; 9 had a missing apartment number; 9 were sent to an address with no mailbox; 2 were sent to vacant addresses; and 21 were returned for some other reason.

Ineligible by conviction: The organizers of one pre-election jailhouse absentee ballot drive conducted a records check on 400 inmates who had signed up, found 18 ineligible, and alerted election officials; no votes were cast by these ineligible persons.
376 individuals allegedly rendered ineligible by felony conviction cast ballots, based on an attempt to match voter rolls and information from the Department of Corrections. 96 individuals listed as voting in Milwaukee matched name, address, and birthdate against Department of Correction records, and 182 individuals listed as voting matched only name and address. At least one appears to have been erroneously listed as voting; he is listed as voting but claims that he did not, while his wife is not listed as voting, but did cast a ballot. Another 98 people listed as voting elsewhere around the state matched name, address, and birthdate against Department of Correction records, but at least 7 were convicted after the election, and were eligible at the time they cast their ballot.
13 voters have been formally charged with fraudulently voting while ineligible; of these, 7 have been convicted, 1 voter was acquitted, 1 case was dismissed upon evidence that the voter was eligible when voting, 2 cases were dismissed for other reasons, and 2 cases were dismissed despite evidence that the voter was ineligible. In one of the latter cases, the voter provided his Department of Corrections identification card at the polls, which had “OFFENDER” printed in bold letters across the face, but was not told that he was ineligible to vote.

3 others were documented as voting while ineligible but have not been charged. An additional voter documented as ineligible was found in 2006.

Double voters: A computer glitch in Milwaukee caused at least 314 voters who re-registered before or on Election Day to be listed twice on the rolls, with a notation of voting next to each listing. Each was given only a single ballot.
83 people allegedly voted twice; 14 allegedly voted both absentee and in person, 9 allegedly voted in Milwaukee and other cities, 59 allegedly voted twice in Milwaukee, and 1 allegedly voted twice in Madison.205 Of the 59 voters alleged to have voted twice in Milwaukee, most registered twice but voted only once. 51 were cleared by investigators, 1 was acquitted at trial, 1 received no verdict at trial, and 1 was found incompetent to stand trial.
Finally,another voter named Gloria Bell believes that she was confused with a woman named Gloria Bell-Piphus.
Of the 9 voters alleged to have voted both in Milwaukee and in another city, all 9 were cleared of wrongdoing: clerical and scanning errors by poll workers accounted for 6 of the voters, 2 were fathers and sons alleged to be the same person, and 1 had a different middle name and birthdate from his alleged double.
Of the 14 voters alleged to have voted both absentee and in person, in at least 12 cases, after comparing absentee records to poll records, the absentee ballot was not counted.

Dead voters: 4 votes were cast in the names of allegedly dead people.208 These were all absentee ballots, cast by individuals who died within two weeks of the election; it is not clear whether the ballots were cast before the individuals died.

Impersonation: 1 vote was allegedly cast in the name of an individual who did not vote. Further investigation of the alleged vote cast in the name of another was determined to be a clerical error by a poll worker.

Fictitious voters: 2 votes were allegedly cast in the name of an individual who could not be verified as an actual individual.212 These votes were cast in the name of Marquis F. Murff, who could not be verified by a reporter as an actual individual. We are not aware of any further public investigation.

Underage voter: One ballot was cast by a 17-year-old voter, using his real birthdate.

Noncitizen: One columnist reported that a ballot was allegedly cast by a Canadian legal permanent resident. We are not aware of any further public investigation.

Faulty registration: Four individuals allegedly submitted false voter registration applications. 2 Milwaukee residents were convicted for submitting false voter registration applications; 1 person alleged to have supervised two others who turned in false forms was also convicted, but that conviction was overturned. The trial of one other individual accused of submitting false registration applications is still pending. No votes were alleged to have been cast under these registrations.