(CNN) House Speaker Nancy Pelosi is facing pressure from within her own leadership ranks to take a more aggressive strategy toward impeachment even as Pelosi made clear that she is pursuing a deliberate approach.

House Judiciary Chairman Jerry Nadler discussed with Pelosi the advantages of an impeachment inquiry in terms of adding weight to a court case, according to a source with direct knowledge. Nadler, whose committee has been on the front lines of investigating the findings from within special counsel Robert Mueller's report, broached the topic with Pelosi because several members of his committee have been pressing to open an inquiry.

The House Democrats' debate took place behind closed doors in several meetings Monday evening -- in Pelosi's leadership office, in a larger meeting of the Democratic steering committee and in the House Judiciary Committee.

Pelosi made clear to Nadler that Democratic-led investigations won a key court case earlier Monday and their approach is getting results, according to the source. Pelosi made a similar case at the larger Democratic meeting and Nadler agreed with that approach when they met.

The tensions displayed behind closed doors underscore the growing divide within the caucus about how to proceed in the face of White House resistance to all its demands, as Pelosi and some of her top confidants argue that acting with too much haste would be a gift to their political foes while a growing faction of Democrats -- that now includes several high-profile and high-ranking members -- push them to take a tougher stand against what they call a lawless President.

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