Once the public testimony begins the number of those supporting impeachment will grow. Have you noticed virtually no Republicans and Trump supporters will answer the basic question... "Is it ok for a US President to ask the leader of a foreign country to investigate a political opponent?" They know the answer and it's obvious to the American people why they won't answer.
Something I learned just today was very telling... the US Aid to Ukraine, which was held up all summer, was released just 2 days after the whistleblower report. Coincidence? Not likely.