"If proven, some of this would be impeachable, yes," Nadler said on Meet the Press. "Obstruction of justice if proven would be impeachable."
However, Nadler said House Democrats have not opened an impeachment inquiry. The judiciary chairman's comments come on the heels of the release of a redacted version of Mueller's investigation into Russian interference in the 2016 presidential election and whether or not the Trump campaign conspired with the Kremlin.
Mueller documented extensive ties between Russians and Trump campaign officials, but concluded that there was not sufficient evidence to establish a conspiracy.
On obstruction, Mueller pointedly declined to exonerate Trump, laying out several instances in which the president sought to curtail the Russia investigation.
Several leading Democrats have called for impeachment proceedings against the president in the wake of the Mueller report. Massachusetts Sen. Elizabeth Warren, a 2020 presidential candidate, on Friday called on Congress to begin the process of removing Trump from office through impeachment proceedings.
But House Speaker Nancy Pelosi, prior to the release of the Mueller report, had stated that she opposes impeachment due to Republican control of the Senate and over concerns that it would only further divide the country.