The CIA has accused Russia of interfering in the 2016 presidential election by hacking into Democratic and Republican computer networks and selectively releasing  emails. But critics might point out the U.S. has done similar things. 

The CIA has accused Russia of interfering in the 2016 presidential election by hacking into Democratic and Republican computer networks and selectively releasing  emails. But critics might point out the U.S. has done similar things. 

The U.S. has a long history of attempting to influence presidential elections in other countries – it's done so as many as 81 times between 1946 and 2000, according to a database amassed by political scientist Dov Levin of Carnegie Mellon University.

That number doesn't include military coups and regime change efforts following the election of candidates the U.S. didn't like, notably those in Iran, Guatemala and Chile. Nor does it include general assistance with the electoral process, such as election monitoring.

Levin defines intervention as "a costly act which is designed to determine the election results [in favor of] one of the two sides." These acts, carried out in secret two-thirds of the time, include funding the election campaigns of specific parties, disseminating misinformation or propaganda, training locals of only one side in various campaigning or get-out-the-vote techniques, helping one side design their campaign materials, making public pronouncements or threats in favor of or against a candidate, and providing or withdrawing foreign aid.

In 59% of these cases, the side that received assistance came to power, although Levin estimates the average effect of "partisan electoral interventions" to be only about a 3% increase in vote share.

The U.S. hasn't been the only one trying to interfere in other countries' elections, according to Levin's data. Russia attempted to sway 36 foreign elections from the end of World War II to the turn of the century – meaning that, in total, at least one of the two great powers of the 20th century intervened in about 1 of every 9 competitive, national-level executive elections in that time period.

Italy's 1948 general election is an early example of a race where U.S. actions probably influenced the outcome.