President Trump is tweeting once again about immigration and “partisan Dems” intent on impeachment.

“The American people deserve to know who is in this Country. Yesterday, the Supreme Court took up the Census Citizenship question, a really big deal. MAKE AMERICA GREAT AGAIN!” Trump said in his first Wednesday morning tweet.

The Supreme Court heard oral arguments Tuesday on whether the 2020 Census may ask people for their citizenship status.

On Dec. 12, 2017 the Justice Department asked the Census Bureau to reinstate a citizenship question on the decennial census to provide data on the voting age population. The Justice Department said that having such data would permit more effective enforcement of Section 2 of the Voting Rights Act, which protects minority populations.

But Democrat opponents strongly object. They say noncitizens will be less likely to fill out the Census form if they are in the country illegally — as millions of them are — and that could lead to inaccurate data.

The decennial census is mandated by the Constitution, and the results are used to apportion Congressional seats and allocate federal funds.

In two other tweets on Wednesday, Trump warned about continuing problems at the U.S. border:

A very big Caravan of over 20,000 people started up through Mexico. It has been reduced in size by Mexico but is still coming. Mexico must apprehend the remainder or we will be forced to close that section of the Border & call up the Military. The Coyotes & Cartels have weapons!

Mexico’s Soldiers recently pulled guns on our National Guard Soldiers, probably as a diversionary tactic for drug smugglers on the Border. Better not happen again! We are now sending ARMED SOLDIERS to the Border. Mexico is not doing nearly enough in apprehending & returning!

President Trump also indicated that impeachment is on his mind, and he outlined his thoughts on dealing with it, if it happens:

“The Mueller Report, despite being written by Angry Democrats and Trump Haters, and with unlimited money behind it ($35,000,000), didn’t lay a glove on me. I DID NOTHING WRONG. If the partisan Dems ever tried to Impeach, I would first head to the U.S. Supreme Court. Not only are there no “High Crimes and Misdemeanors,” there are no Crimes by me at all. All of the Crimes were committed by Crooked Hillary, the Dems, the DNC and Dirty Cops – and we caught them in the act! We waited for Mueller and WON, so now the Dems look to Congress as last hope!”

The Trump White House is refusing to allow former and current White House officials to testify before various House committees, something that is sure to lead to continuing legal battles. Trump told the Washington Post that the lawmakers issuing the subpoenas are “obviously very partisan.”

And in a letter dated Tuesday, Treasury Secretary Steve Mnuchin told the chairman of the House Ways and Means Committee that President Trump’s personal and business tax returns will not be produced “unless and until it is determined to be consistent with law.”

Mnuchin called the request for Trump’s tax returns “unprecedented,” and he said he expects to give the committee a final decision by May 6.