House Democrats will now "conduct investigations Republicans wouldn't conduct," and Americans will see President Donald Trump's tax returns, Rep. Eric Swalwell, who won re-election in California, said Wednesday.

"We'll fill in the gaps on the Russia investigations," the California Democrat, a member of the House Intelligence Committee, told NBC's "Today." "The American people will see his [President Trump] tax returns, not because of any voyeuristic interest, but because they should know if he is corrupt. "

Further, Swalwell said, "we will look at the cashing in of access to the Oval Office...and his financial entanglements overseas.”

Meanwhile, Swalwell said he is concerned special counsel Robert Mueller's investigation into Russian meddling in the 2016 election could be in trouble.

"I think the best thing we can do as Republicans and Democrats is pass (in) the Senate legislation (to) protect Mueller in the House and put that on the president’s desk," said Swalwell. "I expect there will probably be more indictments in the next coming weeks if you just look at the number of grand jury witnesses heard from in the past few weeks.”

Swalwell added that he expects House Minority Leader Nancy Pelosi, D-Calif., to return to the speaker seat she once held, but he also thinks there should be more "fresh blood" in the House.

"I'm the youngest member of the leadership team," he said. "I had conversations in the last few days with members in our caucus who will be seeking leadership positions and stepping up. I think you're going to see transformational leadership coming.”