Could someone please explain the meaning of the following paragraph?

Republican lawmakers seized on the political leanings of some on Mueller's team and claimed the former special counsel had violated longstanding precedent by explaining his decision not to recommend charges against the president.
(5th paragraph)


Context>>>>>>>>>>>>>>>>>>>>>>>>>>>.
The former special counsel during his testimony rejected Trump’s repeated charges that the Russia probe was a “witch hunt.” He also doubled down on his assertion that his report on the investigation did not "exonerate" the president.

Mueller's investigation did not establish that there was a conspiracy between the Trump campaign and Russia during the 2016 election, and neither implicated nor exonerated Trump on the question of obstruction of justice.

The former special counsel's testimony hewed closely to his report and he declined to answer questions beyond its scope, though he did say during his testimony that a president can be indicted once they leave office.

Trump said it was “dumb” to ask whether he could be indicted after leaving office, even though Mueller said the possibility exists.

Republican lawmakers seized on the political leanings of some on Mueller's team and claimed the former special counsel had violated longstanding precedent by explaining his decision not to recommend charges against the president.

Trump took note of those Republicans, praising them as “incredible warriors” who were “defending our country.”

He also asserted that Democrats were “devastated” and claimed that “their party is in shambles right now."

“They’re going to lose the 2020 election, including congressional seats, because of the path they chose,” Trump predicted.