The idea that Bush is the only candidate brave enough to take on Trump is a theme strongly embraced by his campaign and supporters in recent days. The campaign has released several slickly produced anti-Trump videos — including one released Monday that faults Rubio, Cruz and New Jersey Gov. Chris Christie for failing to confront Trump. When Trump accused Bush on Twitter of distorting his statements, the Bush campaign replied later with a web-only video to bolster his points…

The super PAC had vowed to focus on positive advertising, but its ads are now roughly two-thirds negative and one-third biographical, according to a person familiar with its plans who requested anonymity to speak frankly about the group’s strategy…

Another Bush bundler, who requested anonymity to discuss campaign strategy, said that “conventional wisdom for a long time was don’t bash Trump because it would hurt you. Well, Trump has thumped Bush enough, the poor bastard, that by hitting back it might just move his numbers up. This may be less about bringing down Trump’s numbers but instead to bring Jeb’s numbers up because he’s standing up to the guy. And nobody else is trying this. He’s showing that he’s not a low-energy, let-the-bully-get-away-with-it kind of guy.”