President Trump on Thursday night promised to tackle Obamacare repeal once more, just as soon as the Republican tax cut bill as signed into law.

"Obamacare premiums are going up, up, up, just as I have been predicting for two years," Trump tweeted. "Obamacare is OWNED by the Democrats, and it is a disaster."

"But do not worry," he continued. "Even though the Dems want to Obstruct, we will Repeal & Replace right after Tax Cuts!"

ObamaCare premiums are going up, up, up, just as I have been predicting for two years. ObamaCare is OWNED by the Democrats, and it is a disaster. But do not worry. Even though the Dems want to Obstruct, we will Repeal & Replace right after Tax Cuts! — Donald J. Trump (@realDonaldTrump) November 23, 2017



The Senate's failure to pass any bill to repeal or overhaul Obamacare is what prompted Republicans to quickly move to tax cuts this year. And it remains a difficult problem for Republicans who have spent years calling for repeal of the healthcare law, but were unable to find a way to agree on how to do it this year, despite Republican control at all levels of the federal government.

Republicans are trying to take a nibble out of Obamacare as part of the tax bill. In part because the Supreme Court said the law's individual mandate penalties are a legal tax, some in the GOP are hoping to zero out that penalty in the bill cutting taxes for individuals and businesses.

But it's not clear Republicans can even agree to that. The Senate returns next week in the hopes of passing a tax bill, and will likely have to decide in the coming days whether to include language on the mandate.

But taking up a new healthcare bill again may be a tall order. Many Republicans found it difficult to agree to language that would scale back Medicaid expansion under the law.

Another competing factor could be the Alabama Senate race in December. If Democrat Doug Jones defeats embattled Republican Roy Moore, Republicans will have just a 51-49 majority in the Senate, making it even harder to pass a bill.

Yet another factor is all the other competing agenda items facing Republicans.

Trump himself said this week that welfare reform would be the next item on his agenda, not Obamacare.

"We’re looking very strongly at welfare reform, and that’ll all take place right after taxes, very soon, very shortly after taxes," Trump said at the White House.