Mr. Reid, 69 years old, is facing mounting criticism in his home state and is trailing in the polls against two Republican challengers for his Senate seat: former University of Nevada at Las Vegas basketball star Danny Tarkanian and Nevada Republican Party Chairwoman Sue Lowden. According to an independent Mason-Dixon poll Aug. 23, Mr. Reid lagged behind Mr. Tarkanian by 49% to 38% and 45% to 40% against Ms. Lowden. More on GOP