The biggest areas of concern in illegal voting falls in the major metor areas and particularly inner cities areas in states without significant voter ID requirements. Often people are allowed to enter the polling places and cast ballots by simply declaring they are registered voters and furnishing a name for the polling place workers. There are no identification such as photo ID issued by a state or other political agency which would have required some kind of proof of eligibility. In many such places, there are coordinated 'get out the vote' activities in which literally bus loads of 'voters' are gathered in various locations and then transported to the designated polling places to enter in mass and vote. When non-citizens and or non-residents are permitted to vote, either in person or by electronic or mailin methods, there is no reliable way to prevent fraudulant ballots from being cast and counted.
The Dems (Hillary and DNC) and the green party (Stein at their sponsorship) filed legal actions to try to force 'recounts' in Michigan, Penn, Wisconsin, Florida based on allegations of these sorts of voting fraud, all based on the theory that certain precints which were highly Democrat dominated in terms of registration numbers prior to the election did not produce as many Dem votes as they had 'expected'. As the recounting proceeded, it did show up literally hundreds or a thousand or more votes wrongly cast or counted incorrectly. Ironcially, the results actually shorted Trump and longed Clinton in Wisconsin. When the recounting/rechecking process got going in Michigan and PA, it started suggesting some major voting irregularities in those states favoring Clinton over Trump. When the word got out, the Clinton campaign hastily sought Court relief to stop the process from going forward to keep the issue from being publicly divulged.
From my reading on the subject, it appears the biggest problems in terms of improper vote numbers are focused in certain counties, cities and precints. Chicago, Lousiana, Cleveland, Detroit, Palm Beach, etc are notorious for irregularities. A couple counties in the Cleveland OH area literally had more votes cast for Obama that there were registered voters and in Cayoga County, he actually received 100% of the votes it was reported. This is unquestiionably illegal voting.
The other area where there is grave concern about vote fraud is in the manipulation of the vote recordation and not so much the voter themselves - where a vote from Trump is actually recorded as a vote for Clinton or vice versa (although I have never read of any of the latter happening anywhere). This is the biggest problem with any kind of electronic or machine voting methods and would be glaring if ever they get to allowing electronic voting from home. There would simply be NO WAY to control who is voting in somekind of internet or telephonic scheme. In person with valid, uptodate photo ID with recently verified residence validation is the ONLY way to ensure that there is not wide spread disenfranchisement of the American voters.
