I would say yes, if you visited the department you are interested in.
Last year I went with one of my peers to visit several different graduate institutions over spring break (mid March). Before we went, he had recieved two rejection letters and nothing from the rest of the schools. Shortly after the visits, he received acceptance emails from most of the schools we visited. This could have been due to the timing, but I tend to believe that the visit did sway the opinions of the faculty we met with.
Of course, this could have the opposite effect if you make a bad impression.