Barack Obama’s choice of Joe Biden as a running mate looks like fairly simple calculus, notes Massimo Calabres in Time: his strengths bolster Obama’s weak points. Biden has logged six terms in the Senate; he’s a foreign-policy expert; and he’s a Catholic popular with blue-collar white voters. Perhaps most importantly, he’s a political firebrand.
"Biden''s biggest edge in the homestretch may have come, paradoxically, from his greatest liability: his personality," Calabres writes. "Obama is charismatic, but in tough political confrontations he can be cautious and reserved. A running mate who can add passion to the coming battles, Biden has a fire-in-the-belly quality Obama lacks."