4:00 PM PT -- Hard to tell if it's related, but the Prez just tweeted in all caps ... "MAKE AMERICA GREAT AGAIN!"

Trump's tweet could be regarding his current struggle with Canada to reach a new NAFTA deal ... or he may have just felt the need to repeat his oft-used slogan. Just as likely, though ... it's a retort to Meghan's eulogy for her father.

Wolf Blitzer doesn't think anything at John McCain's funeral was out of line or too political ... and he's got no apparent issues with Meghan McCain's shot at the Prez either.

We got the CNN anchor at the Reagan National Airport in D.C. Saturday shortly after the late Senator's service wrapped up ... he said it was a beautiful funeral, fitting for "a great American and a great patriot."

Wolf also supported Meghan's comments about her father and the country, clearly slamming Donald Trump's "Make America Great Again" motto.

Meghan said, "The America of John McCain has no need to be made great again because America was always great."

Blitzer's on board with that sentiment, telling us though America's made mistakes, it's the greatest country in the world in his opinion ... and "it's always been great."

As we reported ... former Presidents and McCain rivals George W. Bush and Barack Obama also delivered eulogies for the esteemed politician's National Memorial Service Saturday.