Yet Rudy Giuliani, who shares Christie’s hawkish views and lashed out at Ron Paul for making comments about Iraq and 9/11 that were restrained by comparison, is a Trump fan too. The three men have similar styles. The two politicians have surely interacted with Trump as a donor to political causes, while Rubio and Cruz have mostly been sources of irritation.

The genuinely important issues that led to Giuliani’s election as mayor of New York City in 1993 — crime, corruption, one-party misrule, the sense that New York had become an ungovernable city — had racial undertones like many of the controversies associated with Trump.

Christie has mostly picked fights with government workers and their unions, occasionally rebuking conservatives he thought were engaging in anti-Muslim bias. But he’s no stranger to the controversies of the 1990s and likely senses we are in a similar political climate right now.

So it makes a certain amount of sense that Christie is standing with Trump rather than Rubio. And it is no coincidence he made his allegiance known at a time when it was most likely to step on the positive headlines Rubio had generated.