Russian hackers didn’t just attack the DNC and the DCCC (and various Republicans whose information mysteriously never leaked)—they went after voting systems in 39 states, Bloomberg reports. In Illinois:

In early July 2016, a contractor who works two or three days a week at the state board of elections detected unauthorized data leaving the network, according to Ken Menzel, general counsel for the Illinois board of elections. The hackers had gained access to the state’s voter database, which contained information such as names, dates of birth, genders, driver’s licenses and partial Social Security numbers on 15 million people, half of whom were active voters. As many as 90,000 records were ultimately compromised. [...]

In Illinois, investigators also found evidence that the hackers tried but failed to alter or delete some information in the database, an attempt that wasn’t previously reported. That suggested more than a mere spying mission and potentially a test run for a disruptive attack, according to the people familiar with the continuing U.S. counterintelligence inquiry.

When the federal government sent alerts about the Illinois intrusion to other states, 39 total found evidence of hacking attempts. So why didn’t the hackers alter votes? One possibility is that they backed off after a high-level warning from the Obama administration. But:

Another former senior U.S. official, who asked for anonymity to discuss the classified U.S. probe into pre-election hacking, said a more likely explanation is that several months of hacking failed to give the attackers the access they needed to master America’s disparate voting systems spread across more than 7,000 local jurisdictions.

Such operations need not change votes to be effective. In fact, the Obama administration believed that the Russians were possibly preparing to delete voter registration information or slow vote tallying in order to undermine confidence in the election.

Consider two things: several months of hacking may not have been enough to figure out how to most effectively disrupt voting across 7,000 local jurisdictions, but Russia now has until November 2018, or November 2020, to master that. And the Obama administration responded forcefully (in private, while staying all too silent publicly). Do you think Donald Trump, who benefited from the 2016 efforts, is going to do anything to seriously back Russia off of interfering in elections?