President Donald Trump has done it all without any real input from Congress, which, despite Republican majorities in both houses, must still move methodically and is therefore stagnant.

That's nothing particularly new in Washington; to the victor of a presidential election go the spoils of controlling the executive branch, which decides how exactly to execute the nation's laws. Among Democratic President Barack Obama's first acts were undoing policies of Republican President George W. Bush. And so on.

But the impact of Trump's actions could pull at the thread of immigration and immigrants woven into the fabric of American society.

Obama was derided as the "deporter in chief" by immigrant groups for his own role in deporting undocumented immigrants. He focused on "criminals." But Trump's decision to reinterpret that word sets the stage for a much larger and sweeping effort.

Neither man changed law. Obama, like Bush before him, tried to pass sweeping immigration reform that would have created a pathway to citizenship. There's no talk of new laws or immigration reform at the moment.

"People are surprised to hear we do not need new laws," Trump said after signing the executive actions to deal with immigrants and begin construction of a border wall. "We will work within the existing system and framework. We are going to restore the rule of law in the United States."

Trump is taking that notion and running with it. And the repercussions, at least most immediately, will be felt by the nation's immigrants, particularly those who traveled to the country illegally.

The new administration's plan to give law enforcement more leeway in undocumented immigrant detentions, to veer away from allowing immigrants to stay in the country while their cases are adjudicated, and more -- it's all part of the law and how it is interpreted.

Trump's reinterpretation of immigration law -- although his administration says it will not target every undocumented immigrant -- is causing fear in that community because there are so many unanswered questions.

"We're just simply trying to execute what Congress and the President has asked us to do," said an official briefing reporters about the new enforcement posture, according to CNN's Tal Kopan. "We're going to do so professionally (and) humanely ... but we are going to execute the laws of the United States."

The administration says it will not target undocumented immigrants brought to this country as children. But it could.

"I love these kids, I love kids," Trump said of so-called Dreamers during a wide-ranging and wild news conference February 17 . "I have kids and grandkids. And I find it very, very hard doing what the law says exactly to do and, you know, the law is rough.

"I'm not talking about new laws, I'm talking the existing law, is very rough, it's very, very rough."

It's a similar story on the travel ban for new refugees and for visitors from seven majority-Muslim countries that Trump tried to enact shortly after taking office.

His travel ban, while it was in effect, caused chaos at airports because it was enacted in secret and came as a surprise, without first warning the many arms of the government, including Congress.

A federal appeals court hit pause on that order, but Trump is tailoring a new one, and he doesn't expect to need help from Congress. He's tailoring the new order to get by the courts without seeking new legislation.

"We can tailor the order to that decision and get just about everything, in some ways, more. But we're tailoring it now to the decision; we have some of the best lawyers in the country working on it," Trump said at the news conference.

Whatever he releases, expect it to be challenged in court by the state attorneys general -- mostly from states that voted against Trump last November -- banding together against his actions.

Trump antagonists have less power in Congress, although Democrats, if they remain united, can ice new legislation in the Senate. He'll need Congress to pay for his wall, for instance. He'll need Congress to reform the tax code.

But on other impactful initiatives, they won't have the ability to put ice on anything.