Larry Noble is the former general counsel of the Federal Election Commission (1987-2000). He is a CNN contributor and has served as general counsel of the Campaign Legal Center and executive director of the Center for Responsive Politics. The opinions expressed in this commentary are solely those of the author; view more opinion at CNN.

(CNN) Rarely does a day go by without President Donald Trump and his minions falsely claiming Robert Mueller's investigation into Russian interference in the 2016 election completely exonerated him and found "no collusion" and "no obstruction."

Anyone who has actually read the two-volume report on the investigation knows it provides hard evidence that Russia interfered in the 2016 election for the purpose of helping Trump's election, high-ranking campaign officials had contacts with Russian agents about the campaign, and Trump tried to stop or hinder the investigation into those activities.

In fact, by the end of the investigation , Mueller had charged 34 people and three companies, and obtained seven guilty pleas and one conviction, for crimes ranging from interfering with the 2016 election to lying to investigators.

However, Mueller did not charge anyone based on the allegations that the Trump campaign was involved in Russian efforts to interfere in the 2016 election; instead he said his investigation into the contacts between campaign officials and Russians did not produce evidence sufficient to prove they cooperated in a criminal conspiracy or sustain a conviction under the specific provisions of campaign finance laws.

Those interested in finding the truth, and not motivated by self-preservation, understand that Mueller did not say it was legal for a campaign to accept help from a foreign government. Nevertheless, in an interview this week with ABC News, Trump said he didn't see anything wrong with listening to a foreign government offering him dirt on a political opponent and wouldn't necessarily report it to law enforcement authorities.

Not surprisingly, Mueller's handling of the obstruction of justice allegations has received the most attention. After presenting a strong case that Trump attempted to obstruct justice, Mueller did the unexpected and declined to decide whether Trump's behavior "constitutes a federal offense," citing Justice Department policy prohibiting prosecution of a sitting president.

At the same time, he went out of his way to make clear that while the report "does not conclude that the President committed a crime, it also does not exonerate him" and included a not-too-subtle invitation for Congress to continue to pursue the matter.

So far, much less attention has been accorded the result of the special counsel's investigation into the numerous contacts between the Trump campaign and foreign agents. Central to this part of the report is the special counsel's decision "not to pursue criminal campaign-finance charges against (Donald) Trump Jr. or other campaign officials for the events culminating" in a June 9, 2016, meeting between Russian agents and Trump Jr., Jared Kushner and Paul Manafort, who attended the meeting after receiving an email chain indicating that the campaign would receive derogatory information from Russia about Hillary Clinton.

Even the reports about Donald Trump Jr. being interviewed Wednesday by the Senate Intelligence Committee for a second time seem to indicate the main concern was possible discrepancies between what he told the committee and what he told Mueller about his father's knowledge of events.

It would be a major mistake to let stand the Trump administration's claim, echoed by most Republicans in Congress, that Mueller's decision not to bring criminal charges is the final word and a stamp of approval on the campaign's interaction with Russia.

The report makes clear that the "events could implicate the federal election-law ban on contributions and donations by foreign nationals," and the decision not to pursue criminal charges was an exercise of prosecutorial discretion. It was not the result of Mueller concluding that a campaign seeking assistance from a foreign government is legal.

However, the Trump campaign's actions after the report's release should serve as a clear warning it has not ruled out inviting help from a foreign government.

The offer

According to the report, on June 3, 2016, Donald Trump Jr. received an email with an "offer" from "Russia's Crown prosecutor" to the Trump campaign to provide "official documents and information that would incriminate Hillary and her dealings with Russia and would be very useful." The material was described as "very high level and sensitive information" and "part of Russia and its government's support to Mr. Trump."

Trump Jr. responded, "(I)f it's what you say I love it especially later in the summer." After additional discussions, he scheduled a meeting with Russian representatives and invited Kushner and Manafort. Trump Jr. also sent the complete email chain to Kushner and Manafort.

During the meeting, held in Trump Tower, Trump Jr., Kushner and Manafort were told that two brothers who "had engaged in tax evasion and money laundering" had donated to the Democratic National Committee or the Clinton campaign. According to the report, "Trump Jr. asked follow-up questions about how the alleged payments could be tied specifically to the Clinton Campaign," but was told that the Russians "could not trace the money once it entered the United States." Apparently, not impressed with the information, Kushner "became aggravated and asked, "(W)hat are we doing here?'"

The Federal Election Campaign Act (FECA), 52 U.S.C. §30121(a)(1), prohibits foreign nationals from "directly or indirectly" contributing "money or other thing of value" in connection with any US election. Another part of the law prohibits a person from "knowingly soliciting, accepting or receiving contributions or donations from foreign nationals." If a person acts knowingly and willfully, meaning with general knowledge that their actions were unlawful, and the value of the contribution is $2,000 or more, it is a criminal violation. If the value is $25,000 or more, it is a felony.

When Trump Jr. replied he loved it to the offer of free Russian opposition research intended to help his father win the election, and then attended a meeting that included Kushner and Manafort to receive that information, he solicited an illegal contribution from a foreign government.

Why Mueller didn't prosecute

Mueller declined to prosecute for two reasons.

First, he said he was concerned the government could not prove Trump Jr., Kushner and Manafort "were familiar with the foreign-contribution ban or the application of federal law to the relevant factual context."

Apparently, Mueller believes it is reasonable to assume that top officials and advisers to a candidate for a major party presidential nomination, all of whom had access to experienced campaign lawyers, were ignorant of the ban on accepting support from a foreign government, one of the most basic provisions in federal campaign finance law. If so, he set a dangerously low bar for the level of legal compliance expected from a presidential campaign and raised the value of claiming ignorance of the law.

Second, Mueller believes the government might encounter difficulty in determining the value of a contribution that took the form of factual derogatory information.

However, as the report acknowledges, FEC regulations, 11 C.F.R. § 100.52(d)(l) , define "anything of value" as including "the provision of any goods or services without charge," and FEC Advisory Opinion 2007-22 held that a campaign would violate the foreign national prohibition if it accepted campaign materials without charge from a foreign national, even though "the value of these materials may be nominal or difficult to ascertain."

The Mueller report further recognizes that "damaging opposition research is surely valuable to a campaign" and there are several ways you can arrive at its value. For example, you can find out what someone would normally charge to provide such opposition research or look at what it costs to gather and provide the information.

Nevertheless, Mueller concludes that such evidence "would likely be unavailable or ineffective in this factual setting" because the description of the offered information was general and nonspecific and nothing of value was delivered at the meeting. Mueller also suggests that Trump Jr.'s response that "if it's what you say I love it especially later in the summer," could reflect uncertainty in the value of the information.

This is a strained view of the evidence and ignores the very law cited. It is possible "official documents and information that would incriminate" your opponent provided by an adversarial foreign government that supports your campaign is priceless in that you could not buy it. But it is a stretch to say that a presidential campaign would not pay a high price for such information, if it were on the market.

Trump Jr.'s response does not reflect uncertainty in the value of what is being offered, only uncertainty as to whether the material would be as described. It is irrelevant that his concerns were valid, and they did not receive what they were expecting. The ban is on soliciting a foreign contribution. It applies even if the foreign government turns down the request or fails to produce the contribution.

Mueller even acknowledges that "(a) foreign entity that engaged in such research and provided resulting information to a campaign could exert a greater effect on an election, and a greater tendency to ingratiate the donor to the candidate, than a gift of money or tangible things of value." Buying influence is exactly what the campaign finance laws are supposed to prevent.

Yet Mueller decided not to enforce the law. It is unclear whether he considered the likelihood that the campaign would engage in this very activity again.

Trump campaign keeps its options open

The redacted version of the Mueller report was made public April 18. Not surprisingly, it wasn't long before the Trump campaign suggested it was keeping open the option of soliciting help from a foreign government for the 2020 campaign.

In early May, Rudy Giuliani, one of Trump's attorneys, announced he was going to the Ukraine to meet with the president-elect to urge him to pursue an investigation into links between Joe Biden's son and a Ukrainian gas company. While Giuliani canceled the trip after receiving bad press, the campaign never suggested it did so because it was illegal to seek help from a foreign government.

Kushner took it to the next level in a recent interview with Jonathan Swan for Axios. When Kushner was asked whether he would call the FBI if he received an email offering the Trump campaign help from the Russian government, he refused to answer, saying it was a hypothetical question. Besides, he added, he never received the information he was promised the last time that offer was made.

This is like asking someone who stole silverware from your house whether he would steal from you again and him responding it was a hypothetical question and, besides, the silverware he stole the first time turned out to be worthless. It's unlikely you would invite him over again. However, Donald Trump is running for re-election in 2020.

And Trump's quick dismissal of the idea he should reject an offer of free opposition research from a foreign government during his interview with ABC News should dispel any lingering doubts about his view of foreign interference in our elections.

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In his report, Mueller quotes Brett Kavanaugh, then writing for a three-judge court in Bluman v. FEC in 2012: "(T)he United States has a compelling interest ... in limiting the participation of foreign citizens in activities of democratic self-government, and in thereby preventing foreign influence over the US political process."

With this in mind, Mueller may have believed that explaining both the ban on soliciting and accepting foreign national contributions and his concerns about the evidence would deter future campaigns from seeking help from foreign governments, while avoiding the potential risks of filing criminal charges. If so, he may have been a little too optimistic.

The Trump campaign assessed the potential risks and benefits of again seeking Russia's help in 2020 and has decided to leave that option on the table.

Let's hope Congress has the will and time to make it clear to the Trump campaign that working with a foreign government to help you get elected is never an option.