(CNN) House Speaker Nancy Pelosi finally announced on Tuesday that the House would move formally into an impeachment inquiry against President Donald Trump, but the timing of her decision as well as how the process will unfold has given some Democrats pause, worrying that the speaker may have acted days too soon.

Several Democratic aides told CNN that some in the caucus are quietly expressing reservations that Pelosi's announcement came before the transcript of the July 25 phone call between Trump and Ukraine's President was released and before Congress received the whistleblower's complaint

In recent days, dozens of members have announced support for impeachment, but for moderate members that backing has come with strings attached. Members running in tough districts or facing reelection in places President won in 2016, were careful to make their newfound calls for impeachment conditional: If it is true Trump withheld military funding to Ukraine in order to elicit dirt on a political opponent, then that would be an impeachable offense.

But, Pelosi's announcement could make it harder for Democrats to backtrack if allegations against Trump don't materialize once the whistleblower complaint and official transcript of the call between Trump and Ukraine's President are released. A senior Democratic aide with insight into moderate Democratic thinking told CNN that many members would have preferred for Pelosi to wait until the end of the week once the contents of those documents were known.

Another Democratic aide said there is grumbling about what happens if the transcript and report are not the "smoking guns that everyone is hyping them to be."

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