Delaware Senator Joe Biden will spend a total of 15 days in Iowa this August to — in his words — show he’s serious about running for president. Biden says the person who secures the Democratic party’s 2008 presidential nomination will not be the one who comes up with the “big idea” but the one who comes up with the answers to the big questions.

Biden suggests these are the crucial questions: “Who is most capable of making this country safer and restoring America’s place in the world in terms of foreign policy and what are the ideas that the Democratic candidates as for how to leveling the playing field for average Americans?”

Biden contends Democrats needs to choose a nominee with “unimpeachable credentials” on foreign policy. “If that person does not have a well-thought-out and explainable rationale for what they believe America’s position in the world to be, what the future is going to look like for this country, how he or she will conduct America’s foreign policy, then I don’t think they can win even if the voters agree with them on every single other issue,” Biden says.

Biden has been a United States senator representing Delaware since 1972. In 1987 — when he was 42 years old — Biden ran for president but dropped out of the race after he used a portion of a British’s politician’s speech without revealing the words weren’t his own.

Biden, who’s now 63, says he was properly chastened by that experience and has spent the past two decades focused on foreign policy issues. The next president had “better know how to connect the dots” between the world’s top leaders, according to Biden. “The public’s going to demand it,” he says.

Biden is campaigning today (Tuesday) alongside Dave Loebsack, the Democratic candidate in Iowa’s second congressional district against Republican incumbent Jim Leach.