Note well that the issue isn't that Trump won counties. It is that when one compares counties that are side by side and demographically similar, Trump won by an average of a 7% margin HIGHER only in those counties that used electronic voting machines. 7% is, frankly, an enormous factor given the large populations involved. But that isn't the problem. It is the p-factor. What is the probability that this PATTERN of events is due to random chance variations?
Here it is a no-brainer. The p-value for the null hypothesis "The election was fair" is basically zero, if there is a 7% marginal difference between electronic and non-electronic voting that is almost entirely biased in one direction. You don't even have to do a computation -- p has many zeros before the first 1, especially if the pattern persists over three different states, even more so if they are the CRITICAL states, even more so if they are states where polling before the election consistently got an entirely different result that would almost perfectly be explained by the 7% surplus.
What this is really saying is that there is almost no STATISTICAL doubt that the election was tampered with on a grand scale. The only remaining questions are: Who are the perpetrators (I personally doubt the RNC who honestly wouldn't dare, but somebody in Trump's campaign, a group of Trump-supporting hackers, or the Russians are all plausible alternatives, with IMO the Russians being way, way at the head of the line) and Did they leave behind any hard evidence of the exploits? It is going to be difficult to sell a statistical argument, no matter how compelling, to a population that doesn't even know what a p-value is, but any hard evidence at all of an exploit of even one machine would be enough to create constitutional chaos. Any evidence that tied the exploit to (fill in the blank) some specific group would lead to an overturn of the election, maybe even the election(s) (down into the Senate and House and state offices). Any evidence that ties in either the Russians or anyone at all in Trump's campaign will spark a large scale congressional investigation and, quite possibly, prosecution for treason of all involve in the one case, and a SERIOUS, GLOBAL escalation of tension in the other. You almost have to hope that it is an anonymous group just because of the danger to the world if it is the Russians and the damage to the country if it is any Republicans in or outside of Trump's campaign.
At the very least, the congressional investigation will open up Trump's true financial situation and start looking for hard evidence that he is controlled, financially or otherwise, by the Russians. For example, do they have evidence of him having sex with (fill in the unsavory blank)? Do they hold enough of his business debt that they can bankrupt him overnight? Is Melania his handler? His behavior towards the Russians has been "peculiar" throughout his campaign. This would explain a lot.