A couple Republican consultants spell out 12 reasons (they'll provide some later arguing why he might not) but one sticks out for us, especially in 2301.
Forty percent of Americans now see the president as a moderate. That’s up 10 percentage points from a year ago. More importantly, 44 percent of independents now call Obama a moderate, up from 28 percent a year ago. If congressional Republicans are viewed as strident and over-reaching, Obama will be well positioned as a moderating force—with or without any Clintonian triangulation.
This fits with a general point we will make when we discuss elections. The candidate or party that captures the center - the moderates - tends to win.