Massachusetts Rep. Stephen Lynch says that a few months ago he didn't think it would be a good idea for the House of Representatives to seek President Donald Trump's impeachment. Now he wants to be a leader in the process.

Lynch announced this week that he plans to run for the chairmanship of the House Oversight Committee, a seat that would have a prominent role in impeachment proceedings, and he spoke with Boston Public Radio Friday about the impeachment inquiry.

"Back in August when all this started happening, we had evidence from the Mueller report, however we didn't have any votes in the U.S. Senate, since every single Republican senator said they would not support impeachment," Lynch said. "I believe if we had [started the impeachment process then], Trump would've spiked the football after he was acquitted and it would've given him a boost against whoever the Democratic nominee would've been."

Lynch said after Congress and the public learned of Trump's July 25 phone call with Ukraine president Volodymyr Zelenskyy, he thought there was enough evidence to have a winning case for impeachment.

"We have direct evidence from the president's phone call, we have corroborating evidence, we have physical evidence and I think we will prove our case to the American people that the president broke the law," Lynch said. "In fact, we got every single Republican Senator to support an impeachment inquiry, and that is a sea change that is clearly different from what we had earlier on, when I was reluctant."

Lynch is a Democrat representing Massachusetts' 8th Congressional District.