Jon Ralston (@RalstonReports), the man who knows Nevada politics the best, just tweeted the following:

I am hearing Democrats had huge day in Clark County today -- gained 9,600 voters, went over 70,000 lead. Waiting for final numbers...

I don't know Nevada, but Ralston has previously tweeted about Clark County (which contains Las Vegas and has about 70% of the total vote in NV) early voting numbers: "If it's 70K, Dems will be thrilled. Doubt it will be." I think this is a pretty good sign for us to carry NV. With NV, OH, and WI, Barack is reelected. It ain't over yet, and we keep on with GOTV, but things are looking pretty good...