Tom Perez, chairman of the Democratic National Committee. (Justin Lane/EPA-EFE/Shutterstock)

The chairman of the Democratic National Committee on Sunday defended a new multimillion-dollar lawsuit against the Russian government, the Trump campaign and WikiLeaks, with talk show hosts asking whether it was distracting from efforts to rebuild the Democratic Party.

“I don’t know when Director Mueller’s investigation is going to end, so we need to file now to protect our rights,” Tom Perez said in an interview with ABC News’s George Stephanopoulos, referring to special counsel Robert S. Mueller III’s investigation into Russian interference in the 2016 election. “We’ve got elections coming up in November. It’s hard to win elections when you have interference in elections. They’ve done it with impunity, and I’m concerned that it’s going to happen again. So, that’s why we did it now.”

The lawsuit, news of which was first reported by The Washington Post, has been mocked by Republicans as well as the Democratic Party’s left-wing critics. While email hacks of the DNC, the Democratic Congressional Campaign Committee and Hillary Clinton campaign chairman John Podesta caused months of headaches for the party during the election campaign — including the forced resignation of Rep. Debbie Wasserman Schultz (Fla.), the party’s longtime chair — many supporters of Sen. Bernie Sanders (I-Vt.), Clinton’s challenger in the Democratic primary, said the party was refusing to reckon with its decline.

“They still haven’t done a postmortem of why they lost the election, because the explanation for everything is Russia,” said Tim Canova, a Sanders supporter who challenged Wasserman Schultz in her 2016 congressional primary and is now challenging her as an independent. “They were losing midterm elections before anything got hacked.”

In a Friday tweet, President Trump wrote that Democrats had “sued the Republicans for Winning” and encouraged his party to “counter and force them to turn over a treasure trove of material, including servers and emails.” On its own Twitter account, WikiLeaks argued that the DNC was distracting from a previous “moribund publicity lawsuit” and that the anti-secrecy organization was “constitutionally protected from such suits.”

But Perez, who had no role at the DNC during the 2016 campaign, told NBC News’s Chuck Todd that the lawsuit was necessary to protect both the committee and U.S. elections. He said he was “confident that we will get a jury trial” and added that he had “not consulted Hillary Clinton to ask her permission” before filing the complaint.

“We had people on our team who got death threats,” Perez said. “When you do that to people on my team — yeah, I’m gonna punch back.”

Since the 2016 election, even as Democrats have scored unexpected victories in state and congressional races, the DNC’s brand has not recovered from the damaging hacks. Several civil suits have been filed against the DNC by Sanders supporters, who argue that the content of emails released by hackers showed that DNC employees conspired to help Clinton win the Democratic nomination.

The emails produced no evidence that the primaries had been skewed — states and state parties, not the DNC, control primaries and caucuses. But numerous conspiracy theories grew out of the email hack. The family of Seth Rich, a DNC staffer who was killed outside his home in July 2016, has filed two lawsuits against media outlets that suggested that Rich, not hackers, released the email trove as a way of getting justice for Sanders.

Under Perez, the DNC has struggled to get past the hacking story. While Democratic campaigns and other party committees have experienced a fundraising surge, the DNC has badly lagged behind the Republican National Committee. Since the 2016 election, the RNC has raised $171.6 million to the DNC’s $87.7 million. In March, as Democrats celebrated the victory of Conor Lamb (Pa.) in a congressional race in which Republicans had spent heavily, the RNC nearly doubled the DNC’s receipts, raising $13.9 million to the DNC’s $7 million.

On Sunday’s talk shows, Perez said the DNC was acting responsibly by suing now. “A year ago, people were saying: File a lawsuit,” he said on NBC. “I didn’t do it then, because I believe in doing your homework.”

Pressed on how much the lawsuit might cost — a worry for Democrats in cash-starved red states — Perez said it was “hard to put a price tag on preserving democracy.” After Todd played back criticism of the lawsuit from Rep. Jackie Speier (D-Calif.) and Sen. Claire McCaskill (D-Mo.), Perez said the fight would be worth it.

“I disagree with them for the simple reason that our democracy is priceless,” Perez said. “We can’t afford not to do this. It’s hard to win elections when you have interference in elections. And we’ve been winning elections.”