Bill Clinton To Bushes: Why Aren't You On Twitter?

President Bill Clinton issued a Twitter challenge to two other former presidents, George H.W. Bush and George W. Bush, on Wednesday evening.

Clinton posted a tweet saying he received a copy of "41: A Portrait of My Father," the younger Bush's biography of his famous dad. At the end of the message, he included a hashtag asking both men why they have not yet joined Twitter:

Received my copy of #41 by #43, George W. Bush. Touching tribute! #HowAreYouSTILLNotOnTwitter #PresidentialTweeters pic.twitter.com/ECWvElzG44

- Bill Clinton (@billclinton) November 12, 2014

A spokesman for the Bush family did not immediately respond to a request for comment about Clinton's Twitter challenge.

George W. Bush has said he wanted to write the book because he wanted his father, who is 90-years-old, to have a chance to read it while he was still alive.

There has recently been mounting speculation the Bush dynasty could eventually include a third president with mounting speculation another one of George H.W. Bush's sons, former Florida Gov. Jeb Bush (R), could mount a White House bid in 2016.