(CNN) A federal judge on Thursday cast doubt on a civil lawsuit brought against the Trump campaign and Roger Stone by three Democrats who claim that election-year WikiLeaks releases destroyed their reputations.

The hearing put Trump campaign lawyers in the position of arguing in court that there was no collusion between President Donald Trump's campaign and the Russians -- a drama that played out on the one-year anniversary of special counsel Robert Mueller's criminal investigation into exactly that matter.

"We didn't possess the emails, we didn't disseminate the emails and we didn't hack the emails," said Trump campaign attorney Michael Carvin, referring to the Democratic National Committee email leak.

Carvin argued that even if there had been discussion between Russia and the Trump campaign to change the party's platform and influence voters to oppose Hillary Clinton, "that conspiracy is not about an unlawful act," he said. "That's all quite legal. It's called democracy."

Carvin's arguments also seem to preview points he could make in fighting a lawsuit brought by the Democratic National Committee against several Russian and campaign affiliates. Carvin argued Thursday that the Trump campaign shouldn't be held liable for the acts of individuals on the campaign, after the Democrats' lawyer in court pushed the possibility that George Papadopoulos' and Paul Manafort's contacts with Russian-connected individuals during the campaign, and Michael Flynn's contact afterward, helped execute a conspiracy.

Read More