President Obama answers questions Friday in what could be the last news conference of his presidency. (Chip Somodevilla/Getty Images)

President Obama used his final pre-Christmas news conference to tout anew the popularity of the sprawling health-care law that his successor wants to abolish, announcing that sign-ups in Affordable Care Act market­places just hit an all-time record for a single day.

The president said 670,000 Americans chose health plans in states relying on on Thursday, the original deadline to have ACA coverage in place by Jan. 1. That is 70,000 more than the enrollment on the same date last year — a record at the time.

His announcement was part of a flurry of ACA statistics that the administration has released this week to buttress its contention that President-elect Donald Trump and Republican congressional leaders will pay a price in public opinion if they carry out their pledge to repeal the law and replace it with more conservative policies.

At his end-of-year news conference in 2015, Obama gave a running enrollment tally, saying that nearly 6 million people had signed up by the deadline for coverage on New Year’s Day.

This week’s increased interest prompted federal health officials on Thursday to give consumers four extra days to choose coverage, saying that about 1 million people had been in a virtual waiting line because the website and federal call centers were too busy to immediately accommodate them.

Thursday was the deadline to sign up to have Affordable Care Act coverage in place by Jan. 1. (

Officials said midweek that about 4 million people had signed up between Nov. 1 and Sunday. The total includes the 39 states relying on

Obama and his aides have emphasized that, while Trump has said the law’s repeal will be a top priority, any change in health policy would not eliminate ACA insurance for the coming year. For their part, GOP leaders in Congress maintain that they do not want to cause any abrupt jolt in Americans’ health coverage.

A House leadership aide said this week that a transition from the ACA could take two to four years. The aide, speaking about internal discussions on condition of anonymity, said House Speaker Paul D. Ryan (R-Wis.) was committed to guaranteeing Americans “universal access” to insurance but not necessarily universal coverage.