What I saw was a reduction in favor to 37% immediately after Barr have his "report". Now Trump has jumped the shark with his responses and investigations are likely not to remain hindered without severe negative impact.
Lets look at the only historically similar situation
Nixon and his ratings.
Please read the whole thing if you like but Nixon was far more liked than Trump.
Even so look at 1973. Nixon was in great trouble even allowing for sentiment against the VN War. As facts came out there was a point that no AG nor staff member could protect him. Nixon became unstable, withdrawn, vicious and even less concerned with the rule of law as his highest priority was to cover his ass.
That is what we seen now, an AG covering for the modern version of Nixon with outlandish reasoning unsupported by facts, to the point where Special Counsel confronted and called Barr on it. Trump retreats into the imagined invulnerability of EP and learns that there is no refuge there. Barr knows all this and the last thing he wants is to give a court a chance to do the same thing and so obstructs when much could be settled by him not doing the job of the courts and ask the courts to give a proper ruling, the very last bloody thing Trump wants.
Back to impeachment. For now Trump isn't as bad off as Nixon, but he was never as popular either. Since the truth brought down a much more popular President the fall for Trump is likely catastrophic and for many similar reasons.
At this minute I believe there are more against impeachment than for, but then again we're not executing impeachment but talking about doing so at some point, as happened with Nixon. If the decision is made to follow through then there is no court intervention needed and Barr and Trump will give in or be spanked by the SCOTUS and then everything comes out and no EP possible. He's stripped naked as ugly as that may be and the Republicans will have to support his abomination in full view and with the backing of the SCOTUS with their decisions already made.
When all is presented it's hard to imagine that people will fail to take notice and what they are taking notice of.
It all comes down to two things, timing and evidence.