The latest CNN poll underscores a grim political reality for the Republican Party, which has removed any separation between itself and President Trump. He is unpopular and on the Russia investigation not credible:

As Robert Mueller's investigation into Russian interference in the 2016 election inches closer to the President, approval of Donald Trump's handling of the investigation has fallen, matching its all-time low in CNN polling. The findings, from a new CNN poll conducted by SSRS, come as half of Americans say they think it is likely that the Mueller investigation will implicate the president in wrongdoing.
In the new poll, Trump’s approval rating for handling the Russia investigation dips to 29%, matching a low previously hit in June of this year. . . . Among Republicans, 51% approve of Trump’s handling of the investigation, a new low by one point, while among independents, 26% approve, also a new low. Just 15% of Democrats approve of the president’s handling of the investigation, up from October but about on par with the level who felt that way earlier this year.
Overall, a majority (54%) continue to say that most of the things Trump has said publicly about the Russia investigation are false, while just over a third say they are mostly true (36%). That’s largely unchanged since August.

It’s a mistake for Trump and his cultists to think that because Mueller’s approval numbers are also down — from 48 to 43 percent, still far ahead of Trump, with 40 percent who disapprove —, that the president is making headway with public opinion. He’s not, and his claim that the investigation is all a “witch hunt” has failed as well. (“59% say it’s a serious matter, 35% an effort to discredit Trump.")

Half of Americans think Trump is personally involved in wrongdoing, as does about a quarter of Republicans (23 percent). Forty-four percent of respondents said the president acted unethically in regard to Michael Cohen’s claim that negotiations continued for a Trump building in Moscow during the 2016 campaign. Twenty-six percent say it was unwise, but not unethical, while hardcore Trumpists (23 percent) found nothing wrong with it.

Perhaps because of the Russia investigation, his overall approval rating remains at 39 percent. They don’t like his handling of major issues: “Around 4 in 10 approve of the way the president is handling immigration (39% approve), foreign trade (39% approve) and foreign affairs (36% approve).” Interestingly, the president’s climate-change denialism is especially unpopular; only 31 percent approve of his handling of environmental policy.

The intensity of his disapproval (44 strongly disapprove, while only 30 percent strongly approve) remains a consistent problem for him and those who will appear on the ballot with him in 2020.

Republicans who have thrown their lot in with Trump, by smearing the FBI and attacking Mueller, may please the hardcore base but, overall, they are on the wrong side of public opinion — even before the public knows more than a fraction of what Mueller does. If Mueller’s report has concrete evidence of wrongdoing, the true believers who will deny he did anything wrong very well could be below 30 percent. (That doesn’t mean that they necessarily want him to be impeached.)

That is how things stand today. However, does anyone think Trump’s standing will improve as Mueller’s investigation racks up more plea deals and indictments, setting out evidence of Individual-1′s wrongdoing as he goes along? That seems highly unlikely unless — and this is key — Democrats seem to overplay their hand or make the president and his family look sympathetic (as difficult as that might be to imagine.) They are well-advised to let Mueller do the work on Russia while they pursue policy oversight and examine other scandals (e.g., conflicts of interest) and outrages (e.g., Jared Kushner advising Mohammed bin Salman; the handling of hurricane Maria; the family separations policy; the notes from the translator at the Trump-Vladimir Putin meeting in Helsinki).

If Trump, who technically wasn’t on the ballot in 2018, is leading the party in 2020 with poll numbers like this and even more evidence of wrongdoing, Democrats will stand a solid chance of beating him — provided they don’t nominate a candidate unacceptable to a large segment of voters who would otherwise have abandoned Trump.

In short, Trump cultists may be incapable of accepting reality, but the large majority of Americans believe Trump did something(s) wrong and continues to lie about it. Republicans who fear the prospect of another electoral wipeout better start considering their options.