ObamaCare is back under threat as Republicans take control of the Senate after a wave of important victories Tuesday night.



The GOP won pledging to deal blows to the healthcare law, which remains unpopular in its fourth year. And efforts to derail it could gain ammunition starting Nov. 15, if HealthCare.gov encounters more problems in its second enrollment period.

ADVERTISEMENT

Hopes for expanding Medicaid under the Affordable Care Act in five crucial states also appear dashed, after Republicans kept all five governorships on Tuesday.

There is no chance the healthcare law will be repealed with President Obama still in office. Most Republican leaders acknowledge the bulk of the system is too entrenched to root out now, with millions of Americans receiving benefits.



But that doesn't mean there won't be sustained action taken against provisions opposed by Republicans and their allies. Add to that the inevitable symbolic moves — a "full repeal" effort is almost certain — and it means a slew of new healthcare fights are waiting to happen.



Here are five likely Republican lines of attack:



1) The medical device tax



The healthcare law levies a 2.3-percent tax on medical devices that manufacturers say is threatening their competitiveness. The tax was designed to raise revenue for the law's coverage provisions — nearly $30 billion over 10 years.



The House has voted several times to repeal the tax, and there is strong opposition to it in the upper chamber. Sen. Amy Klobuchar Amy KlobucharBattle lines drawn on precedent in Supreme Court fight Sunday shows - Ruth Bader Ginsburg's death dominates Klobuchar: GOP can't use 'raw political power right in middle of an election' MORE (D-Minn.) succeeded in attaching an amendment to the March 2013 budget resolution that called for repeal by a vote of 79-20.



Sen. Mitch McConnell Addison (Mitch) Mitchell McConnellOcasio-Cortez to voters: Tell McConnell 'he is playing with fire' with Ginsburg's seat McConnell locks down key GOP votes in Supreme Court fight Video shows NYC subway station renamed after Ruth Bader Ginsburg MORE (R-Ky.) is expected to put the White House on the spot by holding his own repeal vote. The harder task is coming up with another way to raise revenue and keep the repeal measure budget-neutral.



2) 30-hour rule



Republicans oppose ObamaCare's definition of "full-time" work as 30 hours a week for the purposes of calculating which employers must offer health coverage under the law.



Major private-sector advocates argue that the standard is unreasonable, and Republicans say it's causing businesses to slash worker hours.



Democrats push back on this idea, arguing that raising the standard to 40 hours would make a shift to part-time work more likely.



But there is likely to be significant lobbying clout behind the GOP's case. Some of the largest industry lobby groups in Washington formed a coalition in September to lay the groundwork for a change to 40 hours.



"Unless there is a statutory change to the definition of a full-time employee in the Affordable Care Act, there will be fewer full-time jobs, more part-time workers and fewer overall hours available for Americans to work," International Franchise Association (IFA) President Steve Caldeira said at the time.



3) IPAB



The healthcare law's Independent Payment Advisory Board (IPAB) was intended to reduce costs in Medicare, when the program's per-person spending grows too fast. To do this, IPAB would convene and make recommendations on how to lower Medicare spending, and Congress would be required to fast-track the proposals.



So far, Medicare cost growth is too slow for the board to launch. The panel is also prevented from making recommendations that would cut Medicare benefits.



But Republicans and some Democrats have trained fire on the system, calling it unaccountable and potentially harmful to seniors.



Memorably dubbed a "death panel" by former Alaska Gov. Sarah Palin, it's one provision that's likely to get McConnell's attention next year.



4) Individual mandate



ObamaCare's requirement that almost everyone carry health insurance is perhaps its least popular section.



The "individual mandate" was upheld by the Supreme Court in 2012 and took effect on Jan. 1. Penalties for not complying will start at the end of the tax year, and the Congressional Budget Office estimates that 6 million people will be assessed a fine in 2016.



The rule has never been popular with the public, and in spite of their allies in the health insurance industry, it's possible Republicans will try to repeal it or delay penalties next year.



Obama would never agree to repealing the mandate because it would upend the health insurance marketplaces and cause premiums to increase dramatically.



But Republican leaders will be under pressure to do something to spite the mandate, particularly with any problems that arise during the next tax season.



5) Full repeal



While full repeal of ObamaCare is not possible while Obama is president, many Republicans see it as a core principle that deserves congressional action.



McConnell's team indicated last week that they will pursue full repeal through the budget reconciliation process, which allows language to pass without the 60 votes needed to overcome a filibuster.



The Kentucky Republican drew criticism from conservatives last week, when he downplayed the possibility of passing a full-repeal bill.



Sen. Ted Cruz Rafael (Ted) Edward CruzMurkowski: Supreme Court nominee should not be taken up before election Battle lines drawn on precedent in Supreme Court fight Sunday shows - Ruth Bader Ginsburg's death dominates MORE (R), in a sign of possible flare-ups to come, has urged McConnell to do everything possible to fight ObamaCare. The Texas Republican refused to say Tuesday night whether he would support McConnell for majority leader.