The chart above is from the Monmouth University Poll -- done between July 28th and August 1st of a nationwide sample of 808 adults, with a 3.5 point margin of error.
If this poll is to be believed (and it is a fairly reliable poll), then the televised hearings of the January 6th committee has not changed many minds. While millions watched the hearings, they were evidently the people who had already made up their mind.
The chart below is also from this poll.