Opposition research on Hillary Clinton?
Recent news about the focuses of Special Counsel Robert Mueller's Russian Federation investigation, however, has added another layer Trump would be wise to consider.
Mueller would have the option to issue a subpoena compelling the president to testify if Trump chose not to be interviewed.
Trump has often been praised for how much he loves his children, which seems less like a defining character trait and more like a basic expectation of most humans.
Trump Jr. and other campaign figures, including Jared Kushner, the president's son-in-law, and then-campaign chairman Paul Manafort, attended the meeting with high expectations.
Trump caused a major media uproar over the last few days, not only because he admitted Donald Trump Jr. took the meeting to get dirt on his political opponents, but also because the two repeatedly denied that the meeting was held for that goal.
This development comes as Robert Mueller continues to incorporate Trump's Twitter history into his investigations of Russian collusion and obstruction of justice.
Mueller is probing whether anyone connected with the president's campaign conspired with Russian Federation to tip the election in Trump's favor.
"I'm not going to get into the details, but we were very clear as to the situation involving that trip and the - and the statements that were made to the New York Times".More news: Facebook wants banks to share your personal finances
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JUST IN: White House announces a travel/photo lid, which means no public appearances by Trump today as new questions swirl around that 2016 Trump Tower meeting to get dirt on Hillary Clinton.
It is common for U.S. politicians to research their opponents during a campaign. But there are potential criminal concerns as well.
However, legal experts say that Mr Trump Jr could fall foul of campaign finance laws, which prohibit accepting anything of value from a foreign government or foreign national.
"It depends on motives and knowledge at the time of the meeting".
Trump had earlier claimed that the meeting was about the adoption of Russian children, reported Reuters, a statement contradicted by Trump Jr, who said that the goal was to gather information on Clinton. The statement does not mention that he was promised damaging information about Clinton.
Trump called the reporting a "complete fabrication". Trump Jr. was also told the offer was "part of Russian Federation and its government's support for Mr. Trump". He added that "No details or supporting information was provided or even offered". He initially denied he met with any Russians on behalf of the campaign and now he admits the meeting was to get damaging information about Clinton.
The Trumps' response to the story has been, well, muddy. File Photo by REUTERS/Carlos Barria.
Asked on Sunday why he had denied the president's involvement, one of Trump's lawyers Jay Sekulow told ABC that "I had bad information at that point".
Sunday's tweet was Trump's clearest statement yet on the objective of the meeting, which has become a focal point of Mueller's investigation even as the president and his lawyers try to downplay its significance and pummel the Mueller probe with attacks. Dowd subsequently resigned from the Trump team.