One House Democrat moved quickly Thursday to flex his party’s new majority, introducing articles of impeachment against President Trump.

While that’s not yet on party leaders’ to-do list, another bill announced on the first day of the new Congress that aims to block Mr. Trump from firing special counsel Robert Mueller is likely to see speedy action.

And in the Senate, a key Democrat announced a bill to force Mr. Trump to reveal his tax returns.

The moves signaled that while they have finally grasped some policy-making powers, Mr. Trump remains their dominant focus.

Rep. Brad Sherman of California kicked off the action with his impeachment resolution, accusing the president of obstructing justice by ousting FBI Director James B. Comey and trying to intimidate Mr. Mueller over his investigation into the 2016 election.

“I believe that obstruction of justice is the clearest and most provable high crime and misdemeanor committed by Donald J. Trump,” Mr. Sherman tweeted as he announced the renewed impeachment push.

Newly installed House Speaker Nancy Pelosi, who during last year’s campaigns had tamped down impeachment speculation, said Thursday that she hasn’t ruled it out.

“We shouldn’t be impeaching for a political reason and we shouldn’t avoid impeachment for a political reason. We just have to see how it comes,” she told NBC’s “Today” show.

Rep. Jim Jordan, an Ohio Republican, said Mr. Sherman’s immediate introduction of articles of impeachment was a sign that Democrats are too focused on Mr. Trump.

“We knew they couldn’t help themselves,” he tweeted.

House Minority Leader Kevin McCarthy, California Republican, cautioned Democrats to look to the future rather than settling scores with Mr. Trump.

“We are at our best when we focus not on retribution but on building a more perfect union,” he said in remarks before he handed the speaker’s gavel to Mrs. Pelosi.

But Democrats’ powerful left flank has cheered the anti-Trump efforts, fueling the desire of liberal lawmakers to take some swipes at the president.

One option that could draw bipartisan support is legislation to protect Mr. Mueller’s investigation into Russian meddling in the 2016 campaign and Trump figures’ behavior.

Incoming Judiciary Committee Chairman Jerrold Nadler said his legislation would require the special counsel to be notified of his firing and gives him a chance to challenge the ouster in court. He said as Mr. Mueller looks to finish up his probe, the threat of meddling from Mr. Trump will grow.

“Now is the time for Congress to finally act and pass this legislation to protect the integrity of the special counsel’s investigation and the rule of law,” he said in a statement with other top committee Democrats.

A version of their bill in the last Congress drew bipartisan support in a Senate committee, though the GOP leadership has said it’s not needed and has blocked it from gaining floor action.

More partisan is the legislation to force Mr. Trump to reveal his tax forms.

Sen. Ron Wyden, the top Democrat on the Senate Finance Committee, said it has been a tradition for four decades for presidential nominees to disclose their tax information to the public. His bill would write that into law and force sitting presidents to release three years of tax returns as well.

Tax returns are generally considered personal private information under the law, and access is severely restricted.

Certain members of Congress do have the authority to look at private returns, but they are bound by secrecy rules. House Democrats have said they plan to use that authority to get a look at Mr. Trump’s records, but Mr. Wyden said his bill is needed to make sure the information can be made public.

Sign up for Daily Newsletters Manage Newsletters

Copyright © 2020 The Washington Times, LLC. Click here for reprint permission.