Two different conventions, very different goals

WASHINGTON (AP) — Barack Obama needs to remind voters why they loved him in 2008. Mitt Romney needs for voters to get to know and like him better.

Both candidates want to host flawless political conventions to gain the upper hand ahead of the campaign's fall homestretch.

Republicans and Democrats alike agree: Obama and Romney both must try to strike a balance with their conventions. They need to fire up their core backers without alienating undecided voters who may well decide a close election.

How each accomplishes that task — or falls short — could greatly influence the rest of the campaign.