A congressional expert in Missouri thinks Republicans will face challenges if they plan to quickly repeal Obamacare once Donald Trump becomes President.

While the Republican majority in the House can abolish the health care law with a simple up or down vote, the Senate is more complicated.

Measures can only be passed there by a 60 percent margin, unless they’re budget related, when only a simple majority is required.

Professor Steve Smith is director of the Weidenbaum Center on the Economy, Government and Public Policy at Washington University in St.Louis.  He notes some parts of Obamacare can be repealed through the budget process, which is known as reconciliation. “Subsidies for people on the insurance exchanges or expansion of Medicaid funding to the states, (both) clearly have financial implications and could be included in reconciliation bills.”

But other parts of Obamacare are not budget related, and will still require a 60 percent margin to be repealed.  One of them is the provision ensuring people with preexisting conditions are covered.

Smith thinks congressional Republicans are now thinking through their options on how to repeal the law and face a complicated situation.  At this point, he says they’re trying to figure out what their options are.  “Congressional Republicans are thinking through those options right now, knowing that some parts of Obamacare can be treated by a simple majority vote in the Senate, and other parts cannot” said Smith.  “So they’re trying to sort this out, and it’s not a simple matter.”

Senate Republican have limited power in the Senate because they control the chamber by a narrow 52-48 margin.

The ramifications of repealing some parts of the health care law while leaving other portions in place have been championed by President-elect Donald Trump.  After initially declaring he’d repeal the entire law as one of his first orders of business with a Republican controlled congress, Trump waffled after being elected, saying some provisions, such the preexisting conditions measure, would remain intact.

Congressional Republicans have yet to coalesce around the idea.  Smith says they’ll need to be careful moving forward.  “Pulling some parts (of Obamacare) out, but not others may leave very incoherent policy that even the Republicans do not want to be responsible for administering”.

A major stumbling block to leaving popular parts of the law in place, while stripping others which help finance it – such as the mandate that almost all individuals purchase health care – is the likelihood that premiums would skyrocket.

One plan being floated by some GOP lawmakers would call on lawmakers to repeal the law in early 2017, but delay the effective repeal for up to three years.  Complete repeal of Obamacare also faces headwinds after recent polling shows only about 25 percent of Americans want to the entire law rescinded.

A Kaiser Family Foundation poll showed 26 percent favor full repeal while 30 percent want it to be expanded and 19 percent want it to continued in it’s current form.