In his final news conference as president Wednesday, Barack Obama vowed to step off the political sidelines if incoming President Donald Trump dares to "round up" children of illegal immigrants, "roll back voting rights" or otherwise engage in "systemic discrimination."

Obama offered hints about his post-White House plans when he indicated he would take a more activist role to defend "core values that may be at stake" under a Trump administration.

"If I saw systematic discrimination [is] being ratified in some fashion. I put in that category explicit or functional obstacles to people being able to vote, to exercise their franchise," Obama said.

He added, "I put in that category institutional efforts to silence dissent or the press."

But it was the DREAMers, or children of illegal immigrants, who got Obama the most fired up.

"And for me, at least, I would put in that category efforts to round up kids who have grown up here and for all practical purposes are American kids, and send them someplace else, when they love this country, they are our kids' friends and their classmates and are now entering into community colleges or in some cases serving in our military ... The notion that we would just arbitrarily, or because of politics, punish those kids, when they didn't do anything wrong themselves, I think would be something that would merit me speaking out."

As WND reported, in June 2012, Obama issued an executive order declaring that illegal immigrants who were brought to the U.S. before they turned 16 and who are younger than 30 would not be deported. They became eligible for a two-year work permit that could be renewed indefinitely under the program called Consideration of Deferred Action for Childhood Arrivals, or DACA. Obama’s executive order mimicked some of the provisions in the DREAM Act, which failed to pass in Congress in 2010.

Obama further expanded his unilateral immigration actions in 2014 to include illegal-immigrant parents under the Deferred Action for Parents of Americans and Lawful Permanent Residents, or DAPA.

While Obama indicated he would take an activist role on such issues, he also noted that he has no plans to run for office.

"It doesn't mean that I would get on the ballot anywhere," Obama added.

Trump has indicated he has plans to roll back many of Obama executive actions. During his campaign for president, Trump promised to "cancel every unconstitutional executive action, memorandum and order issued by President Obama."

As WND reported, in December 2016, Obama lectured Trump about the use of executive orders, telling the incoming president to avoid taking unilateral action.

"Keep in mind though that my strong preference has always been to legislate, when I can get legislation done," Obama said at the time, adding, "... My suggestion to the president elect is, you know, going through the legislative process is always better, in part because it’s harder to undo."

In his last presser Wednesday, Obama also used a football analogy and applauded his administration's role in taking action on same-sex marriage and transgender issues – actions he said are irreversible.

"I'm proud that in certain places we maybe provided a good block downfield to help the movement advance," he said. "I don't think it is something that will be reversible, because American society has changed. The attitudes of young people in particular have changed.

"That doesn't mean there aren't going to be some fights that are important – legal issues, issues surrounding transgender persons. There's still going to be some battles that need to take place," he said.

"But if you talk to young people, Malia and Sasha's generation, even if they're Republicans, even if they're conservative, many of them would tell you, 'I don't understand how you would discriminate against somebody because of sexual orientation.' That's just sort of burned into them in pretty powerful ways."

After a reporter asked Obama a question about race, the outgoing president turned to the issue of voting rights.

"The reason that we are the only country among advanced democracies that makes it harder to vote, it traces directly back to Jim Crow and the legacy of slavery," he said.

Before he gets into any activist role, Obama said he plans to enjoy some downtime in his new home in Washington, D.C.

"I want to do some writing," he said. "I want to be quiet a little bit and not hear myself talk so darn much."