Sept 16 (Reuters) - CNN's live stream of the prime-time Republican presidential debate drew a record online audience for a U.S. primary debate with 920,000 simultaneous viewers after about 90 minutes, the network said on Wednesday. The total midway through the three-hour debate was "by far the biggest audience a primary debate has had on the Internet," CNN said in a blog post on its website. The first nominating contest for the November 2016 election is four months away. Viewership peaked about five minutes later with about 921,000 simultaneous viewers, a CNN spokesman said... More