Democratic Rep. Katie Porter (Calif.), who flipped a long-held Republican district in the 2018 midterm elections, voiced her support Monday for opening impeachment proceedings against President Donald Trump.

"After weeks of study, deliberation, and conversations with Orange County families, I’ve decided to support an impeachment investigation of the President," Porter said in a video posted on her Twitter feed.

Special Counsel Robert Mueller "presented extensive evidence of obstruction of justice that requires continued investigation by Congress," Porter added.

A protege of Sen. Elizabeth Warren (D., Mass.), who taught Porter while she attended Harvard Law School, Porter defeated a two-term Republican incumbent last November and is the first Democrat to represent the Southern California congressional district since it was created in the early 1980s.

Porter’s calls for impeachment make her one of the few congressional Democrats representing a competitive district who are supporting beginning impeachment. New Jersey Democrat Tom Malinowski, who represents the state’s 7th congressional district, told NBC News last month he supports opening impeachment efforts against Trump.

Malinowski and Porter both represent districts highlighted by the National Republican Congressional Committee as top targets for Congressional Republicans in the 2020 election. Congressman Harley Rouda (D., Calif.), another Democrat representing a potential 2020 swing district, has set a self-imposed deadline of June 30 on whether he will support impeachment.

A spokeswoman for the committee said Porter’s support of impeachment will become a major liability for the freshman congresswoman in her re-election bid, pointing to a recent poll in the state showing only 35 percent of registered voters in California support Congress opening impeachment proceedings.

Over 60 Democratic members of Congress now support impeaching the President, which represents more than one-fourth of the Democratic caucus. Speaker Nancy Pelosi (D., Calif.) and other members of the Congressional leadership team have tried to dissuade members from discussions around impeachment, instead encouraging their members to talk about the legislative agenda passed by the Democratic majority.

The Washington Post reported Monday that focus groups conducted in swing states show the Democratic legislative agenda has failed to break through with voters.

"It seems like there is a preoccupation with what’s happening as it relates to the White House, and so everything else sort of gets drowned out," Rep. Charlie Crist (D., Fla.), a vice chairman for the Democratic Congressional Campaign Committee, told the Post.

Freshmen Democrats in swing districts have also voiced concern to Democratic leadership that voters in their own districts are not aware of the legislative activities of the new majority.

With 31 Democrats occupying seats won by Trump in 2016, Republicans have remained confident they can pick up the the districts necessary to regain the majority in 2020.