From left to right, Donald Trump's wife, Melania Trump, daughter Ivanka Trump, and sons Eric Trump and Donald Trump Jr. watch the second presidential debate. (Tasos Katopodis/AFP/Getty Images)

In case there was any doubt, the last 24 hours have sealed it: Donald Trump's family will play a big role in his presidency, if they have anything to say about it.

That's problematic for a host of reasons. But the Trumps appear primed to press the envelope of what's legal and ethical in the new administration.

Trump's daughter Ivanka and her husband, Jared Kushner, appeared in photos of the president-elect's meeting with Japanese Prime Minister Shinzo Abe on Thursday. And the New York Times is reporting that Kushner may test the legal bounds of what he's allowed and attempt to join the Trump administration.

The revelations follow a series of controversies involving Trump's family over the past week. First, Trump's lawyer said that the president-elect's fortune would be put in the hands of his three oldest children -- Donald Jr., Ivanka and Eric Trump. The following day, all three were named to Trump's transition team, helping him pick who will run his administration. Then it was reported that the high-level security clearances were being sought for those three children and Trump's son-in-law -- something the Trump campaign eventually denied.

Donald Trump has a lot of potential conflicts of interest as president – but there's no law that specifically requires a commander in chief to remove themselves from all of their business interests. The Fix's Peter W. Stevenson explains why presidents usually put their assets in a "blind trust" to avoid problems. (Peter Stevenson/The Washington Post)

The first move was already questionable, since it's customary for wealthy politicians like Trump to set up true blind trusts in which they have no real control over their fortunes and don't know how the decisions they make might enrich themselves. And just about everything since then suggests there will be no real firewall between Trump's presidency and his kids; if anything, they might be more involved than we previously thought and certainly more involved than just about any previous presidential children.

Even if Kushner is the only one to technically join the administration -- and it remains an open question of whether he can -- the presence of Trump's children on his transition team and at a high-profile meeting with top world leaders shows just how Trump plans to involve his family in his presidency.

But why is all of this a big deal in the first place? Why wouldn't family members of politicians be allowed to serve in their administrations or take meetings with world leaders?

It traces back to the Kennedys. After President John F. Kennedy appointed his 35-year-old brother, Robert, as attorney general -- a basically unprecedented move at the time, involving an office for which few thought the younger Kennedy was qualified -- Congress in 1967 passed an anti-nepotism law. It reads:

A public official may not appoint, employ, promote, advance, or advocate for appointment, employment, promotion, or advancement, in or to a civilian position in the agency in which he is serving or over which he exercises jurisdiction or control any individual who is a relative of the public official.

But it's not completely clear whether this law applies specifically to White House staff. In other words, Kushner certainly couldn't be a Cabinet secretary, but the Trump team seems to think he could be an adviser. And the possible precedent for that traces back to another famous political family: the Clintons.

When President Bill Clinton appointed his wife, Hillary, to head up his health-care efforts, the couple was sued. It wasn't that the filers wanted to nail the Clintons for nepotism, but given that she could not be an official government employee under the law, they argued that the meeting of her health-care task force should be open to the public.

The appeals court decision that resulted might have given Kushner and Trump hope to get around the law in 2016, though some experts are dubious. Here's the passage from D.C. Circuit Court Judge Laurence Silberman, which was joined in by Judge Stephen Williams:

...We doubt that Congress intended to include the White House or the Executive Office of the President. ... So, for example, a President would be barred from appointing his brother as Attorney General, but perhaps not as a White House special assistant. ... The anti-nepotism statute, moreover, may well bar appointment only to paid positions in government. ... Thus, even if it would prevent the President from putting his spouse on the federal payroll, it does not preclude his spouse from aiding the President in the performance of his duties.

In keeping with this ruling, the New York Times reports that a lawyer whom Kushner has consulted with suggested he forgo a paycheck and put his own holdings into a blind trust.

Granting for the moment that Trump can shoehorn his son-in-law into the White House, though, there remains the question of his proximity to Trump's finances. Trump is already taking heat for not using a true blind trust; the Wall Street Journal editorial board said Friday that he should liquidate his assets and put the cash proceeds in a true blind trust, if only in the name of putting the controversy to rest. As a White House staffer, Kushner would be deeply involved in the decisions that would affect the finances of the Trump Organization that his wife is running.

One could argue that the Trump kids serving on the transition team doesn't give them direct control over the levers of government that could affect their fortune. But Kushner would have access to those levers and have potential knowledge of Trump's fortune that Trump himself is not supposed to have. And Ivanka Trump sitting in on meetings with high-profile world leaders only compounds the possible conflicts of interest.

So, yes, having Trump's children so close to his presidency is already ethically and legally questionable. And tasking them with controlling his fortune while he's in office and potentially giving one of their spouses an official role in his presidency makes all of this very dicey.

But Trump seems to be ignoring the doubters and pressing forward. We'll see how far he can take it.