Washington — Michigan Sen. Debbie Stabenow says she now backs an impeachment inquiry for President Donald Trump.

Stabenow, the fourth-ranking Democrat in Senate leadership and the most senior Democrat in Michigan's delegation, issued a statement Monday backing an investigation, citing concerns about Trump's potential obstruction of justice as described in special counsel Robert Mueller's report.

“The Mueller report describes extremely serious instances of the President of the United States trying to obstruct justice," said Stabenow, chairwoman of the Senate Democrats' Policy and Communications Committee.

"I support the ongoing investigations in the House of Representatives and would stand with my colleagues in the House if they decide to launch a formal impeachment inquiry. No one is above the law."

Stabenow joined Washington Sen. Patty Murray, the assistant Democratic leader, as the highest ranking Senate Democrats to back impeachment.

She also joins four Michigan Democrats in the House who support launching an impeachment investigation, Reps. Rashida Tlaib of Detroit, Brenda Lawrence of Southfield, Dan Kildee of Flint Township and Andy Levin of Bloomfield Township.

Michigan independent Rep. Justin Amash, who left the Republican Party this month, has also said Trump's conduct meets the threshold of impeachment.

No Senate Republicans have come out publicly to support launching an impeachment inquiry, and they remain unlikely to vote to remove Trump from office.

Stabenow's shift comes after Mueller on Wednesday testified for several hours before two House committees on Capitol Hill.

Mueller told lawmakers that he didn't exonerate Trump, that the president in his written answers to investigators "generally" wasn't always truthful, and that he could be charged with obstruction of justice after leaving office.

POLITICO reported Tuesday that Democratic presidential candidate Tom Steyer's group Need To Impeach is expected to broadcast a 30-second ad on CNN during this week's debates in Detroit featuring excerpts from Mueller's testimony.

mburke@detroitnews.com