What Trump could accomplish his first days in office
Immigration was key to the Republican president-elect's campaign platform, and so was repealing and replacing Obamacare.
He has also come out strongly against the nuclear deal with Iran and the Trans-Pacific Partnership trade deal.
We took a look at what Trump could accomplish quickly during his first days in the Oval Office.
Obamacare
The quickest way to nullify President Barack Obama's universal healthcare policy is probably to defund it, something Congress could feasibly do right away.
"We're pretty confident that he's going to get off to a quick start, and he can take action on Obamacare right away if he wants to and can submit that," Lee Edwards, a fellow at the conservative think tank the Heritage Foundation, told Business Insider. "From what we can tell, that's going to be high on his list."
The Heritage Foundation is working with Trump's White House transition team, and Edwards said Obamacare, is likely to be a top priority for the president-elect.
Robert Shapiro, a political science professor at Columbia University, said the way to nullify Obamacare would be to defund it.
"They could pass a bill rescinding it. Period. Done deal," Shapiro said. "… They can do it in a way that cuts off funding."
Cynthia Cox, a health policy expert at the nonpartisan Kaiser Family Foundation, told Business Insider earlier this week that because Republicans do not control a filibuster-proof majority in Congress, they will only be able to use budget reconciliation measures to change the Affordable Care Act.
But Shapiro said there might be a way around that.
"If they're worried about Democrats filibustering it, they can enact what's called the 'nuclear option' and change the rules and eliminate the filibuster," he said.
Under this option, Republicans would only need a simple majority, rather than a three-fifths majority, to end a Democratic filibuster.
Immigration
Reforming immigration laws will be "a little more difficult to do right off the bat," Edwards said.
But there are some things Trump could move on quickly.
"The idea of secure borders, there's a bill right there in the House which calls for 700 miles of double-layered wire fencing, and that could get some immediate action," he said.
Trump has also said he would "immediately terminate" executive orders from Obama that protected 4 million undocumented immigrants from deportation. Executive orders implemented by Obama are indeed reversible once a new president takes office.
Another popular pledge from Trump's campaign was building a wall - not just a fence - on the southern border of the US to prevent illegal immigration from Mexico. He has also insisted that Mexico will pay for the wall.
But it's unlikely that Trump will actually be able to make that happen, according to Shapiro.
"Mexico is not paying for the wall," Shapiro said. "They may want to rethink that."
There's "absolutely no way" for the US to force Mexico to pay for the border wall short of threatening the country.
"We can threaten to invade them," Shapiro said, adding sarcastically, "That would be a nice, smart thing to do."
Trump's administration could also threaten remittances (money transfers) sent from the US to Mexico, something Trump has proposed in the past.
"They could do something with regard to trying to control remittances from Mexicans working in the US so that's the leverage they might have," Shapiro said.
But this plan could have an unintended side effect.
"They may want to think good and hard about that because when remittances go back, they go to families to try to support them so they don't try to immigrate to the United States," he said.
Iran deal
Trump has called the nuclear agreement with Iran "one of the worst deals" he has "ever seen negotiated," but has been somewhat unclear on exactly what he would do about it.
Obama brokered the deal between a US-led group of world powers and Iran that provided guarantees of sanctions relief in exchange for the Middle Eastern country curtailing its nuclear program.
And while Trump has made clear that he's against the deal, he has also admitted that it would be difficult to rescind the deal immediately. He's said that, instead, he might "police" Iran to make sure it upholds its end of the bargain.
But he has also suggested that he would rescind the deal, telling the pro-Israel lobbying group AIPAC that his "number one priority is to dismantle the disastrous deal with Iran."
State Department spokesman Mark Toner has said that Trump could throw out the deal, noting that it's "valid only as long as all parties uphold it." In that case, Trump could reinstate US sanctions against Iran by executive order.
Still, it's unlikely the deal would be nullified immediately.
Trans-Pacific Partnership
Analysts also speculate that the Trans-Pacific Partnership, a free-trade agreement championed by Obama that aims to slash tariffs and promote economic growth among 12 nations in the Pacific Rim, is dead in the water.
Obama had hoped to get the deal passed during the lame-duck session.
"The coffin is nearly closed on TPP," Nate Olson, director of the Trade21 project at the Stimson Center, told Politico. "There's no viable action in the lame duck."
Trump once called the deal "a rape of our country."
Taxes
Trump will also likely want to figure out a tax plan during his early days in office.
"If they're going to cut taxes, they're probably going to want to figure out a more comprehensive tax plan," Shapiro said. "There is consensus about cutting taxes on businesses, there is a consensus on simplifying the tax code in a certain way."
Politico reported Thursday that Republican lawmakers are already discussing ways to cut taxes.
The Supreme Court
Another box Trump will likely want to check as soon as possible is nominating a Supreme Court justice to replace Antonin Scalia, who died in February. Obama nominated federal judge Merrick Garland to take Scalia's place, but because Republicans hold a majority in the Senate and the nomination happened during an election year, the Senate has refused to hold a confirmation hearing for Garland.
Even Senate Republicans who opposed Trump said Congress should wait until the new administration is in place to confirm a new justice.
"[Trump] will want to appoint the successor to Antonin Scalia on the Supreme Court, and there him and the Republican leadership see eye-to-eye," Shapiro said.