It was a bold, headline-grabbing promise. Donald Trump vowed last week that immediately after his inauguration, he'd call Congress into special session to repeal the Affordable Care Act.
The only problem is that he wouldn't be able to do that. When the new president is inaugurated on Jan. 20, Congress will already be 17 days into a new session. The president can call an extraordinary session only for a Congress that has left the Capitol for the year.
"A lot of people who have lived in Washington their entire lives don't understand how Congress works," said Tripp Baird, who served as floor assistant to Trent Lott when he was the Senate Republican leader. "I wouldn't hold that against anyone."
Perhaps. But Trump's vow underscored a fundamental problem he would have as president. Nothing in his long experience as a businessman — the essential selling point of his campaign — compares to governing.
In business, he led companies run by his own family, operated by people he'd hired, and worked with stakeholders all aiming at the same thing, a profit. When he did work with a board of directors, he chafed, writing in his 1990 book, "Trump: Surviving at the Top," that he "personally didn't like answering to a board of directors." In the White House, he'd face a Congress with its own agenda and base of power, a nation full of stakeholders with goals that often would compete with his and an operating system built to work on consensus, not autocratic rule.
It would be — according to those who have worked for him, studied him and worked the levers of power in Washington — a potentially jarring new environment that would test his skills as a CEO and negotiator.
For starters, Trump would take office as the least popular president in modern history, according to a battery of polls. Many Americans, including a large swath of his own Republican Party, think he's not fit to hold office. He also has a fractious relationship with congressional leaders, chiefly House Speaker Paul Ryan, R-Wis.
Some Trump priorities might find support among Republicans, including his call to repeal President Obama's signature health care law. But he almost certainly would not have a 60-vote filibuster-proof majority in the Senate, making it difficult to land much legislation, including his signature campaign promise to build a wall on the southern border with Mexico.
"He's kind of a party of one," said Leon Panetta, the former CIA director and defense secretary who served as chief of staff for former President Bill Clinton. "And unfortunately for him, that party has a limited base of support in the Congress."
Trump could push some things without congressional approval. He pledges to renegotiate the North American Free Trade Agreement and withdraw from a proposed Asia-Pacific trade deal that Obama has championed. He'd also cancel most of Obama's executive orders on immigration.
But Trump can only go so far without a willing Congress, meaning that many of his initiatives, including his call for a massive tax cut, could stall.
"You can be as much of an outsider as you want to be, but if Congress is not buying into your agenda you are just not going to get much passed," said Jonathan Felts, a former White House political director for President George W. Bush.
Trump's presidency would sorely test the Republican Party's concept of a big tent, said William Galston, a former adviser to President Bill Clinton who's now a senior fellow at the center-left Brookings Institution, a think tank.
"His independence from the orthodoxies of both parties could be a double-edged sword," Galston said. Trump would have "freedom of action, but it's questionable he'd have the skills or discipline to work with others while going it alone."
Republican congressional leaders will want progress they can point to for the 2018 congressional elections, said former House Speaker Newt Gingrich, a Trump supporter. He noted that Trump has known likely Senate Democratic leader Chuck Schumer of New York for years and would be able to forge a working relationship to secure some Democratic support.
Trump has promised a hiring freeze for federal employees, the elimination of two federal regulations for every new one and a ban on lobbying.
As an outsider, a unique challenge for Trump may be filling his government with experienced hands. Gingrich said Trump could look elsewhere.
"Appoint none of them," he said. "Not a single one. He can find dozens of fresh new people without using any people who have failed us for the past 15 years."
A go-it-alone approach would be a radical change for an American presidency, which is best run in a collaborative fashion, said Doug Elmets, a Republican consultant based in Sacramento, Calif., who worked in the Reagan White House.
"Leadership skills mean you don't know everything so you surround yourself with great people to give advice," Elmets said.
Trump has run his business and his campaign with a small circle of influence.
"He's quite the micromanager," said author Gwenda Blair, author of "Trumps: Three Generations that Built an Empire." Blair noted that Trump often talks about how he trusts his own instincts and doesn't need experts: "That was his modus operandi in business. Sometimes it worked, sometimes it didn't."