OXON HILL, Md. — In the early stages of the 2016 Republican presidential primary, Gov. Scott Walker of Wisconsin is the hot property, his poll numbers rising and the chatter from activists and contributors growing steadily more positive. Gov. Chris Christie of New Jersey is the mirror opposite, his political stock falling along with his standing in surveys of Republicans.

On Thursday, the opening day of the annual Conservative Political Action Conference here outside Washington, it was as if the two men’s fortunes followed them onstage. Mr. Christie, who declined the opportunity to deliver a prepared speech, appeared before a ballroom with many empty seats, faced adversarial questions from a conservative talk show host and used the opportunity to attack a fellow presidential aspirant, Jeb Bush — a telltale sign that he is fighting to regain position.

A few hours later, Mr. Walker spoke before a standing-room-only crowd, was repeatedly bathed in loud ovations, received only a handful of softball questions after his remarks, and avoided any direct criticism of his potential Republican rivals.

The first primary votes will not be cast for nearly a year in the Republican race, but the contrasting standings of Mr. Walker and Mr. Christie reveal how quickly perceptions of the race can change. Just a few months ago, Mr. Christie was riding high, re-elected in a landslide and bestowing millions of dollars on Republican candidates as the head of the Republican Governors Association, while Mr. Walker was pleading for some of that money in a hard-fought re-election campaign in which defeat could have put a presidential bid out of reach.