Washington (CNN) For all of President Donald Trump's gripes with his predecessor , this could prove the most galling: his entry into television.

After all, it's that the world Trump has occupied for the better part of four decades. It's there he gained his celebrity, molded his reputation and earned enough of a following to make a presidential bid possible.

Now, the man who has consumed Trump's attention for much of his tenure is invading his turf. Former President Barack Obama, along with wife Michelle, are producing partners with Netflix. Their first feature, a documentary about a Chinese-owned factory in Ohio , was announced last month.

The news apparently hasn't pleased Trump. In a set of tweets on Monday, the President urged congressional investigators to "Look at the Obama Book Deal, or the ridiculous Netflix deal" instead of looking at whether he committed obstruction of justice during Robert Mueller's probe.

Later, Trump simplified things: "Obama Netflix?" he wrote, after insisting without evidence he was due to lose billions of dollars as president.

In neither of his tweets did Trump specify what wrongdoing might have occurred in Obama's arrangement with Netflix nor his memoir deal with Random House, which was announced in 2017. Obama's office declined to comment.

But the fresh criticism amounts to the latest evidence of Trump's lingering fixation on Obama, who he's met in person only once since Inauguration Day.

He's accused him of spying on his Trump Tower campaign office. He blames him for a host of foreign policy debacles, from the Middle East to North Korea. And he's claimed his trade policies put America on its heels.

That's not to mention the "birther" conspiracy Trump fueled years before vying for the presidency himself, a racist lie he propagated using regular appearances on Fox News and other television programs. His indignation only deepened when Obama made fun of him during a 2011 White House Correspondents' Dinner speech and television cameras found Trump scowling in the audience.

At the same time, Trump has sought to dismantle some of Obama's chief accomplishments, including on environmental protections and health care. He boasted on Twitter Monday about outpacing Obama's judicial appointments -- an effort mainly fueled by Senate Majority Leader Mitch McConnell, who has pushed Trump's nominees through in the absence of major legislation.

Home turf for Trump

In going after Obama's post-presidency business arrangements with Netflix and Random House, Trump is delving into two arenas -- television deals and book publishing -- he knows well. His book "Art of the Deal" and NBC reality series "The Apprentice" were critical in creating the exaggerated image of a billionaire businessman that helped propel him to the White House. He remains an avid television consumer, watching hours of cable news a day, though isn't known to read much.

"He in very many ways used television to become president, but then TV kind of became the president, because what he was seeing on TV set his agenda and controlled his mood and determined the world that the rest of us would live in," New York Times chief television critic James Poniewozik -- whose book "Audience of One: Donald Trump, Television and the Fracturing of America" came out last week -- told CNN's Brian Stelter on the "Reliable Sources" podcast.

Trump's tweets on Monday targeted deals widely reported to be netting the Obamas tens of millions of dollars. Neither company publicly disclosed the terms of their contracts, but publishing sources placed the book advance north of $60 million for memoirs from both the former President and first lady.

Michelle Obama's book, "Becoming," was the best-selling book of 2018 and one of the most popular political memoirs ever. The former president, meanwhile, has been writing his by hand, and it's not expected to be released until at least next year.

The Netflix production deal, announced more than a year ago, led to the formation of "Higher Ground Productions," which will create a broad range of programming for the streaming service. The first slate included the factory documentary, a drama series about women and people of color in post-World War II New York, and a Frederick Douglas biopic adapted from a Pulitzer-prize winning biography.

Tradition holds?

The Obamas aren't expected to produce programming that is overly political -- a continuation of their preference to largely avoid direct criticism of the current president. That's a pattern other ex-presidents have followed after leaving office.

Usually it's reciprocated to an extent by the sitting president, though past leaders -- including Obama -- have blamed some of their predicaments of the men who came before them. None, however, have gone at it with the same gusto as Trump.

The President has only escalated his attacks as Obama's vice president, Joe Biden, vies for the Democratic presidential nomination. He's accused the duo of agreeing to a "disaster" Iran nuclear deal that allowed "pallets of cash" to be shipped to Tehran, though recently Trump has expressed his own openness to extending the Iranians a line of credit during negotiations.

In talks with North Korea, Trump has lamented the nuclear situation there wasn't handled during previous administrations. He claimed Obama sought his own meeting with Kim Jong Un, the dictator with whom Trump has developed a friendship (Obama's aides deny there were any overtures to Kim).

The only time the men met for substantive talks was at the White House shortly after the 2016 election. Then, Obama warned Trump that North Korea could prove to be his most intractable problem. But Trump has enhanced that warning to claim Obama advised him he'd be at war with the country before long.

Since that meeting in the Oval Office, the two men have barely spoken. They met in person only once, during the state funeral for President George H.W. Bush, exchanging businesslike handshakes in the front pews of the National Cathedral before the service began.