WASHINGTON — The chairman of the Democratic National Committee on Sunday defended a 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 told ABC News’ George Stephanopoulos, referring to special counsel Robert Mueller’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.”

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 of Florida, the party’s longtime chairwoman — many supporters of Sen. Bernie Sanders, I-Vt., Clinton’s challenger in the primaries, 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 Donald 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.”