WASHINGTON — Chief Justice John G. Roberts Jr. twice voted to save President Obama’s health care law, infuriating his usual allies on the right. Now, conservatives are nervous that the chief justice will disappoint them again in a challenge to another major Obama initiative, this one on immigration.

The case, to be argued on Monday at the Supreme Court, presents fundamental questions about executive power against the backdrop of a wrenching national debate over Mr. Obama’s plan to spare millions of immigrants from deportation. But Chief Justice Roberts’s record suggests that he may avoid taking a position on such a divisive and partisan issue, focusing instead on the more technical question of whether the states challenging the Obama administration’s immigration plan have suffered the sort of direct and concrete injury that gives them standing to sue.

That jurisprudential off-ramp would avoid a deadlock or a grand pronouncement from a short-handed court on a politically charged issue in a presidential election year. And that may prove attractive to a chief justice who has said he does not want the Supreme Court to be viewed as a forum where “partisan matters would be worked out.”

A narrow ruling would in some ways echo Chief Justice Roberts’s 2012 opinion sustaining the central feature of the health care law on grounds so carefully calibrated that no other justice joined all of his opinion. And it would be consistent with his stated preference for achieving consensus by defining the legal question at issue in a case as narrowly as possible.