A DHS official told Politico that the voter registration systems from 20 states have experienced intrusion attempts that they consider "probing of concern."  The revelation comes on the heels of warnings from DHS and other federal agencies that hackers may attempt to interfere in the November election.

“It’s reached a threshold of some concern,” the official told POLITICO, cautioning that the majority of states were not experiencing successful intrusions.

The federal government has focused more attention on state voting systems in the wake of confirmed digital intrusions into voter rolls in Arizona and Illinois.

The FBI and DHS asked states to look for hacking attempts coming from the IP addresses linked to those intrusions. That filtering exposed the maelstrom of attacks on state election systems that officials are now trying to analyze.

“It’s not to say that people weren’t constantly trying to probe all these different websites” before the Arizona and Illinois incidents, said the DHS official. “I would imagine they probably were.”

The Associated Press first reported that DHS had seen attempted hacks in more than 20 states. But the DHS official stressed that the AP’s report, along with an earlier CNN story, misunderstood the nature of the cyber threat.

All states are constantly targeted, the official said, not just the states most seriously affected.

“It’s gotten a little bit, I think, blown out of proportion with the general public,” the official said.

Several secretaries of state — who oversee elections — acknowledged that they are constantly flagging potential nefarious digital activity. But very little of this activity actually leads to a breach.

"The fact someone pinged it doesn’t mean there’s a breach," said Colorado Secretary of State Wayne Williams said in an interview Friday.

Williams said his state wasn’t among the ones that had experienced a "probing of concern." But, he added, it’s not uncommon for hackers to make a run at his data trove.

“The fact someone passes by, or runs a quick test on the database and doesn’t get through, that happens every day with every major database,” he said.

Georgia Secretary of State Brian Kemp echoed this assessment.

“We get pings on our systems every day, not just in election, but in our corporation division and other parts of state government,” Kemp told POLITICO earlier this week.

The feds are trying to downplay the intrusions, but the fact that some of the hacking attempts come from I.P. addresses that have been specifically flagged as potentially dangerous should galvanize the government to redouble its cyber-security efforts. 

While the probing hasn't gone all the way to a breach, it may just be a dress rehearsal for election day.  The mischief that hackers could cause by altering voter registration rolls is minimized by backup lists stored outside the network.  But they could still wreak havoc by placing doubts about the integrity of the vote in the minds of citizens.