Gov. Chris Christie of New Jersey has scheduled an Oct. 16 special election to replace Frank R. Lautenberg, the Democratic senator who died on Monday. Mr. Christie will appoint a replacement for Mr. Lautenberg in the interim, but he has yet to announce his pick. His choice of timing for the special election, however, may indicate that he expects the Republican candidates to be weak.

The timing is unusual in that New Jersey will hold its gubernatorial election, in which Mr. Christie will be on the ballot, just three weeks later on Nov. 5. Under state law, Mr. Christie could have arranged for the Senate election to be held on the same day. (He could also perhaps have delayed it until November 2014, although that would have relied on a more controversial interpretation of the state’s statutes.)

One theory is that Mr. Christie is concerned about anything that might interfere with his chances of re-election or suppress his margin of victory. If so, however, the timing of the special election would qualify as exceptionally risk averse, especially for a politician who has a reputation for taking chances. Mr. Christie has an overwhelming lead in polls against the likely Democratic nominee, State Senator Barbara Buono, and he remains extremely popular in New Jersey. There is always a chance that news or political events could intervene between now and November to harm his standing, but his losing the race would be one of the greatest political collapses in recent memory.

Mr. Christie might also be interested in helping Republican candidates for the State Legislature. Democrats control both the Senate and the Assembly, but all seats will be up on the Nov. 5 ballot. With a popular Republican governor heading the ticket and no interference from the United States Senate race, the G.O.P. might have a better chance of winning one or both chambers.

Of course, Mr. Christie could also have used his coattails to help his party’s United States Senate nominee. His move might suggest that his ambitions remain mainly in New Jersey, and less on the national stage. Then again, being re-elected — and having a more successful second term with less Democratic opposition in the State Legislature — could also leave him in a stronger position were he to run for president in 2016.

The implicit thread between all these hypotheses is that Mr. Christie seems to view the Senate contest as a liability. As I wrote on Monday, a strong G.O.P. nominee could potentially make the race competitive, although the Republican would probably remain an underdog. But with a lackluster candidate in a blue-leaning state, the Republicans would be all but conceding the race to Mayor Cory Booker of Newark, the most likely Democratic nominee, who has strong favorability ratings in the state and is expected to build a robust and expensive campaign operation.

While some national Republicans are annoyed with Mr. Christie’s decision, they may not be privy to all the information he had about which Republican candidates might have been interested in Mr. Lautenberg’s seat. It’s plausible that Mr. Christie could have helped a reasonably good G.O.P. nominee to a narrow victory. But if none were interested in the race, it may have been a lost cause.

It may be reasonable to infer, then, that Mr. Christie evaluated the Republican field and did not like what he saw — and that Mr. Booker is poised to win the Senate seat with relative ease.