Obama says it is not possible:
Obama was asked about Trump's voter fraud assertions on Tuesday [..] He responded with a blistering attack on the Republican candidate, noting that U.S. elections are run and monitored by local officials, who may well be appointed by Republican governors of states, and saying that cases of significant voter fraud were not to be found in American elections.That is curious. There are a lot of "non serious" persons in the Democratic Party who tell us that Russia is trying to manipulate the U.S. elections. How is it going to do that when it's not possible?
Obama said there was "no serious" person who would suggest it was possible to rig American elections, adding, "I'd invite Mr. Trump to stop whining and go try to make his case to get votes."
- Harry Reid Cites Evidence of Russian Tampering in U.S. Vote, and Seeks F.B.I. Inquiry
- Hillary Clinton concerned about Russia tampering in U.S. elections
- NSA Chief: Potential Russian Hacking of U.S. Elections a Concern
- Putin's Meddling in the U.S. Elections
Is rigging the election only impossible when it is in favor of Hillary Clinton? This while rigging the elections in favor of Donald Trump, by Russia or someone else, is entirely possible and even "evident"?
That said - I do believe that the U.S. election can be decided through manipulation. We have evidently seen that in 2000 when Bush was "elected" by a fake "recount" and a Supreme Court decision.
The outcome of a U.S. presidential election can depend on very few votes in very few localities. The various machines and processes used in U.S. elections can be influenced. It is no longer comprehensible for the voters how the votes are counted and how the results created.*
The intense manipulation attempts by the Clinton camp, via the DNC against Sanders or by creating a Russian boogeyman to propagandize against Trump, lets me believe that her side is well capable of considering and implementing some vote count shenanigan. Neither are Trump or the Republicans in general strangers to dirty methods and manipulations.
It is high time for the U.S. to return to paper-ballots and manual vote counting. The process is easier, comprehensible, less prone to manipulations and reproducible. Experience in other countries show that it is also nearly as fast, if not faster, than machine counting. There is simply no sensible reason why machines should be used at all.
*(The German Constitutional Court prohibited the use of all voting machines in German elections because for the general voters they institute irreproducible vote counting which leads to a general loss of trust in the democratic process. The price to pay for using voting machines is legitimacy.)