William Galston: “Candidates seeking to succeed a two-term incumbent of their own party face an uphill battle. All other things being equal, political scientists find, such candidates can expect to fall short of the incumbents’ re-election vote share by at least 4 percentage points. Applied to the 2012 results, this metric would yield a 47% share for this year’s Democratic nominee.”
“On the other hand, demographic trends favor the Democrats. As the nonwhite share of the electorate increases, Democrats can expect their baseline to shift upward by 1 or even 2 percentage points in each four-year cycle—a significant gain, but not enough to counter the third-term disadvantage.”
“It is at this point that factors specific to 2016 come into play. To begin, the American people’s assessment of Barack Obama’s performance as president has been rising steadily. From a low of 43% approval as recently as December, it has increased to an average of 49% today… Another potential plus for the 2016 Democratic nominee is the economy’s improving condition… Since its recessionary low, the economy has added more than 13 million jobs, and the unemployment rate has fallen by half.”

