Mueller did not say that Trump was immune from prosecution just by being president, he said the opposite, in fact, it says he explicitly was not found to have committed any crimes at all
Link to the Mueller Report, Quotes:
Page 220: "Under applicable Supreme Court precedent, the Constitution does not categorically and permanently immunize a President for obstructing justice through the use of his Article II powers." [...]""Accordingly, while this report does not conclude that the President committed a crime..."
Page 2: "We applied the term coordination that sense when stating in the report that the investigation did not establish that the Trump campaign coordinated with the Russian government in it's election interference activities."
Page 220: "Second, unlike cases in which a subject engages in Obstruction of justice to cover up a crime, the evidence we obtained did not establish that the President was involved in an underlying crime related to Russian election interference."
Page 9: "Second, while the investigation identified numerous links between individuals with ties to the Russian government and individuals associated with the Trump Campaign, the evidence was not sufficient to support criminal charges. Among other things, the evidence was not sufficient to charge any Campaign official as an unregistered agent of the Russian government or other Russian principal. And our evidence about the June 9, 2016 meeting and WikiLeaks's releases of hacked materials was not sufficient to charge a criminal campaign finance violation. Further, the evidence was not sufficient to charge that any member of the Trump Campaign conspired with representatives of the Russian government to interfere in the 2016 election."
Page 180: "The investigation did not establish that the contacts described in volume I, Section IV, supra, amounted to an agreement to commit any substantive violation of federal criminal law- including foreign-influence and campaign-finance laws, both of which are discussed further below. The office therefore did not charge any individual associated with the Trump Campaign with conspiracy to commit a federal offense arising from Russia contacts, either under a specific statute or under Section' 371's offense clause. The Office also did not charge any campaign official or associate with a conspiracy under Section 371's defraud clause. "
Page 183: "The investigation did not, however, yield evidence sufficient to sustain any charge that any individual affiliated with the Trump Campaign acted as an agent of a foreign principal within the meaning of FARA, or, in terms of Section 951, subject to the direction or control of the government of Russia, or any official thereof. "
Page 185: "The Office considered whether to charge Trump campaign officials with crimes in connection with the June 9 meeting described in Volume I, Section IV. A.5, supra. The office concluded that, in light of the government's substantial burden of proof issues on intent ("knowing" and "willful"), and the difficult of establishing the value of the offered information, criminal charges would not meet the Justice Manual standard that "the admissible evidence will probably be sufficient to obtain and sustain a conviction."
Page 9: "Former Trump Organization attorney Michael Cohen leaded guilty to making false statements to Congress about the Trump Moscow project."
Page 33-35: "The investigation identified two different forms of connections between the IRA and members of the Trump campaign. First, on multiple occasions, members and surrogates of the Trump campaign promoted- typically by linking, retweeting, or similiar methods of reposting- pro-Trump or anti-Clinton content published by the IRA through IRA-controlled social media accounts. Additionally, in a few instances, IRA employees represented themselves as U.S. persons to communicate with members of the Trump Campaign in an effort to seek assistance and coordination on IRA-organized political rallies inside the United States." [...] "The investigation has not identified evidence that any Trump Campaign official understood the requests were coming from foreign nationals."
Page 69: "Cohen was the only Trump Organization representative to negotiate directly with I.C. Expert or it's agents "
Page 70, proof trump declined to work with the Russian government: "In a second email to Cohen sent the same day, Rtskhiladze provided a translation of the letter, which described the Trump Moscow project as a "symbol of stronger economic, business, and cultural relationships between New York and Moscow and therefore the United States and the Russian Federation. On september 27, 2015, Rtskhiladze sent another email to Cohen, proposing that the Trump organization partner on the Trump Moscow project with "Global development group LLC", which he described as being controlled by Michail Posikhin, a Russian architect, and Simon Nizharadze. Cohen told the Office that he ultimately declined the proposal and instead continued to work with I.C. Expert, the company represented by Felix Sater."
Page 101: "The Mueller report firmly establishes there was no connection between Trump and the Russian government. There are claims made that many of the individuals within the campaign had connections to Russia, but that none were criminal in nature, at all, and not just related to a single specific crime."
Cohen was specifically charged with crimes with lying about the supposed "Moscow Tower" meeting on multiple occasions. Finally, the mueller report does state that the president can be charged with a crime, but says they failed to find enough evidence to do so. It's not that complicated, it's actually pretty cut and dry.
Issues with Mueller Report
The support was not just for Trump, Page 31-32: "For example, the IRA targeted the family of [Redacted], and an umber of black social justice activists while posing as a grassroots group called "Black Matters US".
While it is clear that the Mueller report did not establish ANY criminal connection to the and did not say the president was immune from prosecution so this is why they didn't prosecute, there are things in the Mueller report that seem false or intentionally misleading. The most obvious is the report of Michael Flynn who supposedly lied to the FBI, a charge which has thus far been dropped by the DOJ after it was discovered FBI agents intended to catch him int a perjury trap to get him fired, and make and off-the-books deal for him to confess to a crime he didn't commit in order to save his son from prosecution. This is evidence that was revealed after the Mueller report, and thus was probably believed to be true by Mueller and the authors of the report at the time, despite later proven to be false.
Another similar charge is that the Russian disinformation was clearly designed to help trump and hurt Hillary. However, after the facebook advertisements were revealed to the public, many were shown to be explicitly anti-Trump, including holding rallies to protest Trump, supporting Black-lives-matter, an explicitly Anti-Trump organization, and supporting Hillary by suggesting she would be pro-muslim. As these advertisements were declassified, Of these nearly 4000 emails and advertisements, roughly 100 dealt with either candidate, and they were both positive AND critical of both candidates, far from the argument that the Russians supported Trump over Hillary. In fact, it shows the Russians were most likely just trying to sew chaos. It's clear that only a heavily biased interpretation of this evidence would reveal the group, was was "one-step removed" from the Russian government and not even the Russian government, was deliberately pro-Trump.
