Obama has been described as one of the most effective campaigners in American history (his 2008 campaign being particularly highlighted) as well as one of the most talented political orators of the 21st century. Historian Julian Zelizer credits Obama with "a keen sense of how the institutions of government work and the ways that his team could design policy proposals." Zeitzer notes Obama's policy successes included the economic stimulus package which ended the Great Recession and the Dodd-Frank financial and consumer protection reforms, as well as the Affordable Care Act. Zeitzer also notes the Democratic Party lost power and numbers of elected officials during Obama's term, saying that the consensus among historians is that Obama "turned out to be a very effective policymaker but not a tremendously successful party builder." Zeitzer calls this the "defining paradox of Obama's presidency".