Bill Clinton, in his speech before the Democratic National Convention, gave the most succinct and accurate assessment of the Republican campaign proposition:

We left him a total mess. He hasn’t cleaned it up fast enough. So fire him and put us back in.

Trying my hand at this I’d say the Democratic proposition is:

We got the economy in an even worse mess than we thought. We stopped the Great Depression II and got things turned around. Give us more time to improve it.