Former President Bill ClintonBill ClintonRacism: The Left's last refuge Stein: Al Gore needs to 'step up' on climate change Overnight Finance: Trump adviser softens tone on NAFTA | Funding bill to be released Tuesday | GOP leader won't back Trump tariff plan 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.