Representative Jerrold Nadler, the chairman of the House Judiciary Committee, was taken to a hospital after fainting during a news conference on Friday in Manhattan. Mr. Nadler, 71, was seated at a table in a gymnasium at Public School 199 on the Upper West Side, where Mayor Bill de Blasio was heralding the expansion of New York City’s speed camera program. Thirty minutes after Mr. Nadler, a Democrat, made brief remarks, his head appeared to slump. Three medical professionals attended to Mr. Nadler, and Mr. de Blasio helped Mr. Nadler to drink. A fan was turned on and the gymnasium...