It does come after a dip in faith in the FBI. After Comey in early July announced that he would not recommend charges against Democratic presidential candidate Hillary Clinton, positive views of the bureau dropped from 48 percent in June to 40 percent in July.
Then Comey, in late October, made the controversial announcement of more emails discovered in the Clinton probe — an announcement that Democrats still blame for Clinton's loss. By December, just 37 percent had a positive view of the FBI, compared with 27 percent negative, or plus-10.
That plus-10 is now plus-36, with just 16 percent having a negative opinion of the FBI. And views are actually pretty bipartisan. Majorities of both Republicans (54 percent) and Democrats (53 percent) have positive views of the bureau.
It's not clear if the rise in positive views of the FBI owe to Trump having fired Comey, though. They were on the rise even last month, when 45 percent had a positive view. And that was pretty par for the course, actually.
Trump does have a way of making previously unpopular things more popular. Liberals' views on global warming, Obamacare, the Keystone XL pipeline and immigration (most notably, against the border wall) have been ascendant even as the very unpopular Trump has been pushing the opposing view hard. And Democrats who still harbored ill will against Comey and the FBI after the 2016 election have certainly rallied to the defense of the bureau, which is running the most significant investigation into alleged connections between the Trump campaign and Russia.
But it's difficult to argue that the FBI was in dire straits under the leadership of Comey — which may be part of the reason Trump dropped that excuse like a bad habit.