Historically, the vote from Israel has hardly counted. The number of eligible American voters here is now estimated at about 160,000. In 2008, about 30,000 cast absentee ballots. Many here said the process of registering and voting was just too complicated.

But this time as many as 75,000 Americans in Israel have registered for a ballot, spurred on perhaps by the critical issues on the American-Israeli agenda but also by the efforts of iVoteIsrael, a get-out-the-vote group that says it is nonpartisan but that critics accuse of working quietly for the Republicans.

Whatever the reasons — whether the background of tensions between Prime Minister Benjamin Netanyahu and the Obama administration, the looming threat of a nuclear Iran or simply the greater turnout because of efforts by iVoteIsrael — a number of people casting their ballots at an event sponsored by the group said they supported Mr. Romney’s bid.