Trump began his morning tweetstorm with an attack on the federal probe into Russian election meddling before turning to the news of the day: The alleged dangers of allowing immigrants into the country and the purported necessity of separating families at the border.

He doubled down on a false claim he tweeted yesterday, that crime is up in Germany thanks to high rates of immigrants. German crime is at its lowest point since 1992, down 5 percent from 2016, and there is no evidence that Trump has some alternative, unpublished crime data.

Trump also declared that Congress must "change the ridiculous and obsolete laws on immigration. Get it done, always keeping in mind that we must have strong border security."

Democrats have lobbied to end the Trump administration's policy of separating children and adults at the border, and many have accused the president of holding migrant kids hostage in order to extort Congress for money for his long-promised border wall. But Trump also faces growing opposition from his own party and bipartisan consensus has been building put a stop to the practice, though there is no clear legislative path forward.

Sen. Orrin Hatch, R-Utah, told NBC News on Tuesday that he is circulating a letter for Republican and Democratic Senators to sign calling for Attorney General Jeff Sessions to halt family separations until Congress can act.

Many of the migrants are fleeing high levels of violence in Central America.