Tom Perez, the chairman of the Democratic National Committee.

Chairman Tom Perez on Sunday defended the Democratic National Committee’s decision to sue Russia, WikiLeaks and the Trump campaign over Russian election interference, saying the DNC was “protecting our democracy” and could “walk and chew gum” when it came to keeping its focus on the midterm elections.

The multimillion-dollar civil suit was filed on Friday in federal court in the southern district of New York, claiming senior Trump officials conspired with the Russian government in an attempt to damage Hillary Clinton. The suit seeks damages for the hacking of DNC email servers.

Donald Trump tweeted about the suit over the weekend, seemingly promising a legal counter move. “So funny, the Democrats have sued the Republicans for Winning,” he wrote on Saturday. “Now he [sic] R’s counter and force them to turn over a treasure trove of material, including Servers and Emails!”

It was unclear why Republicans would sue to obtain Democratic party emails, many of which are already public owing to Russia-directed hacking that began in April 2016.

Trump’s mention of “Servers” refers to a conspiracy theory he has advanced for more than a year, ironically set off by congressional testimony of then FBI director James Comey, who is currently touring behind a bestselling memoir in which he portrays Trump as “morally unfit” for office.

In January 2016 testimony about an FBI investigation of cyber-attacks including on the DNC, Comey said Democrats had not turned over computer servers but substituted a review of the system performed by the cybersecurity firm CrowdStrike.

“This my folks tell me was an appropriate substitute,” Comey said.

Trump disagrees. On Friday, he wrote: “Just…