2016 was a strong year for Altria Group (NYSE: MO), with the stock jumping 20% to be among the best performers in the tobacco industry. Overall, the cigarette giant has done a good job of finding ways to maximize its profits, and there are reasons why bullish investors think that Altria could sustain its positive momentum in 2017. Yet Altria also faces challenges, and if it makes a misstep, then 2017 could easily become a nightmare year for the company. Let's take a look at what it would take to turn 2017 into Altria's worst year yet.