African-American voters are not nearly as enthusiastic about [Hillary] Clinton as they were about [Barack] Obama.

Obama has built his public image around his ability to bridge divisions - racial, ideological or generational. And that was his reputation, even at Harvard Law School, where he was the first black president of the 'Law Review.

Republican voters are coalescing behind [Donald] Trump, but many Republican elected officials still say they can't support him.

Meanwhile, there are some traditional battleground states - like Ohio and Iowa - that are becoming older, whiter and less educated. That's turning them from true battlegrounds into more reliable red states.

As those states and others in the South and West become more diverse and educated, they will become harder for the Republican Party - in its current form - to win.

Democrats came into the race with a structural advantage in the Electoral College. Their big blue wall - the states that Democrats have won in the past six presidential elections - gave [Hillary] Clinton a strong base to build on.

The Senate is the big prize. Until recently, Democrats felt confident they could get the four seats they needed to take back control if [Hillary] Clinton is in the White House and Vice President Tim Kaine held the tie-breaking vote.