"'He is a chocker. And once a chocker, always a' -- a choker, I guess that's what he meant to say," Rubio said at a rally in Texas, reading Trump tweets from his phone.
Trump misspelled the word "choker" in three tweets Friday, all referencing Rubio after the two had a heated exchange at Thursday's Republican presidential debate.
In one tweet, Trump spelled "choker" both the right way and the wrong way.
"Lightweight Marco Rubio was working hard last night. The problem is, he is a choker, and once a choker, always a chocker! Mr. Meltdown," Trump tweeted earlier Friday morning.
Trump also boasted about his performance at CNN's Republican debate in Houston, tweeting Friday morning, "Wow, every poll said I won the debate last night. Great honer!"
The Republican presidential front-runner misspelled "honor," and his error has spurred both amused and critical responses on Twitter.
Trump later resent the tweets with the corrected spelling.
He also continued his attacks on Rubio, adding some personal criticisms including for Rubio's perspiration after Rubio made some jokes at Trump's expense.
"They don't like Rubio in Florida- he left them high & dry. Doesn't even show up for votes!" Trump tweeted.
He followed up with a picture of Rubio getting makeup applied that said: "Never let them see you sweat."
Neither of those tweets had misspellings.
It is not the first time that Trump, a serial tweeter, has been criticized for his spelling errors online.
Last June, in a tweet slamming one of his favorite Twitter targets, MSNBC host Lawrence O'Donnell, Trump tweeted, "I hear that dopey political pundit Lawrence O'Donnell, one of the dummer people on television is about to lose his show- no ratings? Too bad."