The 2016 presidential election has largely been defined so far by personal attacks and horse race polling. But significant policy differences exist between the candidates, especially Republicans and Democrats. And while those differences will be hashed out on the campaign trail over the next 11 months, some topics are destined to help define the nation's next election.

Here are some of the issues to watch in 2016.

1. The Economy and Jobs

Elections are usually categorized into one of two compartments: the economy or foreign policy.For instance, the 2004 election, just three years after 9/11, was undoubtedly a foreign policy election. In 2008, the election was economic focused as the recession had just begun.

In 2016, it's still unclear if this will be a foreign policy or economic election. Millions of Americans feel left behind as wages have stagnated and the middle class shrinks. But the rise of ISIS and the recent terrorist attacks in the west have revived fears about terrorism.