It is less than a year before the 2016 election — and two candidates for president are in a Twitter flame war.

Jeb Bush, who made an earnest attempt to go after Donald Trump at this week’s debate, is now trying to ridicule the unlikely frontrunner as a “chaotic” candidate that voters can’t trust. On Thursday, he posted this Web video that ran down Trump’s strange facial expressions during the debate:

Jeb also tried his hand at doing a satirical Twitter poll, to depict Trump as a man-child getting his foreign policy from watching children’s cartoon shows (repeating a zinger he used during Tuesday’s debate).

Bush got thrown off his rhythm, however, when he was unable to answer the question of whether Hillary Clinton was more fit to be president than Donald Trump.

And so on Friday morning, Trump went after Bush hard.

Jeb responded to that jibe in the afternoon, accusing The Donald of being unable to remember that Jeb has in fact touted his family ties. But there’s a problem here.

The linked video clip is of Jeb at the Republican debate in mid-September, in which he boldly told Trump, “You know what, as it relates to my brother there’s one thing I know for sure: He kept us safe.” Of course, the wrinkle here is that this was a manifestly false statement, as W. failed both to keep America safe or to wage war against terrorism in an effective manner. (And Trump has occasionally raised this exact point.)

Soon afterward — though it’s not yet clear whether this was a direct response — The Donald hit back extra hard:

Photo: Republican U.S. presidential candidates businessman Donald Trump (L) and former Governor Jeb Bush (R) are seen debating on video monitors in the debate press room during the Republican presidential debate in Las Vegas, Nevada December 15, 2015. REUTERS/David Becker