A contentious, headline-grabbing GOP debate catapulted Fox News Channel to No. 1 among all basic cable networks’ ratings. It’s the second time this year FNC has topped the monthly ratings rankers in total audience. FNC clocked a primetime average of 2.43 million viewers, besting Disney Channel’s 2M, TNT’s 1.93M and USA’s 1.73M, at the top of the total-viewer list. A whopping 25.1 million viewers tuned in to see real-estate mogul/reality-star turned White House hopeful Dona…