About 4 in 10 voters said they had received pre-recorded “robo-calls” about the presidential campaign in March, a big jump over the 25 percent who reported them last November, according to a Pew Research survey conducted March 19-22. In states that have had a primary or caucus, the number is 44 percent, while in those that have not had an election, the number is 16 percent. Congress is currently considering restrictions on the practice.