In the second televised Republican debate, it was made clear that Donald Trump and Jeb Bush did not get along. Out of their many confrontations, the most entertaining moment was when Trump tried to bring Bush down by mentioning his brother, George W. Bush.
"Your brother and your brother's institution gave us Barack Obama," says Trump. "And it was such a disaster those last three months that Abraham Lincoln couldn't have been elected."
Here Trump is using guilt by association to make Jeb Bush seem unfit to be president because he is close with a former president Trump and (he assumes) most of the audience believe was a bad leader. However, Trump seems to be out of touch with the beliefs of the audience.
"As it relates to my brother," says Bush. "There's one thing I know for sure: He kept us safe."
The crowd cheers for Jeb Bush and for their fond memories of his brother. The time immediately after 9/11, George W. Bush's 'shining moment,' seems to still have a profound impact on Republicans today. Jeb Bush even references the very speech where George W. Bush won America's favor, standing with an arm around a fire fighter, standing in the wreckage of the World Trade Center.
Donald Trump obviously did not expect it, and Jeb Bush likely did not expect it either, but Trump's guilt by association technique against Bush turned into a glory by association fallacy, winning over the audience for his rival.