A national poll showed Donald Trump slightly ahead of Hillary Clinton on Tuesday, though, as Nate Silver points out at FiveThirtyEight, cherry-picking polls isn't necessarily indicative of an overall trend: Per the FiveThirtyEight model that analyzed a whole slew of surveys, Clinton appears to still be in the lead by about 3 or 4 percentage points nationwide—a slicing in half of the lead she enjoyed in mid-October. But it's the Electoral College numbers that have Silver declaring Trump as "no longer really a long shot," though he remains the "underdog." In the site's polls-only model, Trump has a 30% chance (as of this posting) of emerging the electoral vote victor, or 31% if you go by the polls-plus model, which includes economic and historical data. And Silver notes even though some are skeptical Trump can nab the needed 270 electoral votes, there are ways in which he could win.
Although a Trump victory is unlikely if Clinton wins the popular vote by 3 to 5 points, a popular-vote win of 2 points or less by either Clinton or Trump opens up various options for Trump to emerge victorious—mainly because it would prove harder for Clinton to hold onto her so-called "firewall" states, and because she wouldn't have a lot of backup options available to compensate for the numbers she may lose in other competitive states. In fact, Silver says Clinton would "probably lose" the Electoral College if the popular vote was precariously close. Still, Heavy.com presents its own electoral map and says Trump would basically need to garner every undecided state to pull off a win—a "tough row to hoe." (Check out FiveThirtyEight and Heavy.com for a more careful look.)