They were stirred up in 16 as well , yet lost the popular vote. Trumps base is not going to get any bigger because of this impeachment proceedings.That tells you the Republican base is stirred up by the process. And you can bet your ass they won't hear or accept any of the evidence, so all it does is rally them behind the orange buffoon.
Democrats have to appeal to those who sat out in protest in '16 and this is their message to them. " Look what your non-action has led to" and get them to the polls.