Did you read the article? In summary:
The survey asked a bunch of questions including questions on whether people were citizens and whether they voted
The Harvard study shows that, not surprisingly, people make mistakes on surveys - check the wrong boxes, or just enter random stuff to screw with the survey people.
So, some people who were not citizens accidentally checked the "i voted" box. Some people who voted accidentally checked the "I'm not a citizen" box. This was just a survey, not some legal document.
Those mistakes make it look like there were a lot of illegal votes that didn't actually exist.
If you had a survey asking people what type of car they owned and one of the options was Lamborghini, don't you think your would get far more people checking the box than there were actually Lamborghini owners? Would you then want to start a big investigation of illegal importation of Lamborghinis?
The original study was probably done in good faith but the methodology was flawed. Social science is hard - its a matter for trained scientists.
I did read that. Any survey can be skewed one way or another, by either illiterate foreigners or by illiterate citizens. It can be skewed by a trick question.
We had a referendum vote here in PA. It was a question. I'm paraphrasing because I can't remember the exact words, but I did not vote for it.
It asked something like, "Do you believe 70 year old judges are too old"?
In Pa, judges are or were forced to retire at age 65. I think. Most everyone in the state has no idea when they are forced to retire. I asked all kinds of "informed" voters, who knew about the presidential election. None of them knew about this age requirement. A judge must be under 66 years of age.
Guess what? They thought it was just a question that would later come out as a vote to raise or lower the age of retirement for judges. Is that what it was? No, it was THE vote to raise the age of retirement to 70 years old.
So, anything can be skewed or lied about. This, to me was a lie.
In fact, anyone who says there are no foreign voters, people do not vote twice, dead folks aren't voting, someone isn't voting for their senile grandpa, or some other illegal voting, is sadly misinformed and living in a world of no accountability or laws, in their mind.