The MLB umpire who vowed to buy an AR-15 and declare a civil war if President Trump was impeached is now apologizing ... saying he didn't "realize the violence in those words."
Rob Drake -- who's been working MLB games since 1999 -- created a firestorm this week when he tweeted, "I will be buying an AR-15 tomorrow, because if you impeach MY PRESIDENT this way, YOU WILL HAVE ANOTHER CIVAL WAR!!! #MAGA2020."
Drake deleted the tweet ... but it was too late -- people were going crazy over it.
Now, after the MLB Umpires Association condemned the tweet, Drake has issued an apology .