Nicholas Maduro, the Venezuelan president declared a 60-day state of emergency on Friday due to what he called plots from within the OPEC country and the United States to topple his leftist government. Mr. Maduro did not provide details of the measure. A previous state of emergency, implemented in states near the Colombian border last year, suspended constitutional rights guarantees in those areas....... Earlier on Friday, U.S. intelligence officials told reporters they were increasingly worried about the potential for an economic and political meltdown in Venezuela and predicted Mr. Maduro was not likely to complete his term.....