Former President Bill ClintonBill ClintonTrump to attend Army-Navy football game Donald Trump will be president — but a President Trump may not be what voters expected Emanuel flips the bird when asked about 2020 MORE late Monday ribbed former President George W. Bush over the 43rd president's lack of a presence on Twitter.

Clinton used the hashtag #HowAreYouNotOnTwitter? in a Presidents Day message to Bush, President Obama and former Presidents George H.W. Bush and Jimmy Carter.

The message was retweeted by Obama's Twitter account.

Clinton was in Haiti with Clinton Foundation partners viewing agricultural and environmental projects.