A flurry of new polls released in the last day or so provides some insight into four questions we’ve been pondering lately:

1. Why is Hillary Clinton’s campaign, which once reportedly considered blowing off Iowa, suddenly working so hard in the Hawkeye State? A new poll finds Clinton trailing John Edwards by a 30-22 percent margin among likely Iowa Democratic caucusgoers. The poll was conducted by the Edwards-friendly antipoverty outfit ONE, but other polls have also suggested that Clinton faces a tougher contest in Iowa than she does nationally. A Washington Post/ABC News poll released earlier this month showed Clinton, Edwards and Barack Obama in pretty much a three-way tie among Democrats who say they’ll turn out for Iowa’s caucuses.

2. Why did John Edwards pull some of his staffers out of Nevada? Yes, the campaign-calendar shuffle has left Nevada looking a lot less important than it once did, but a new Research 2000 poll shows Edwards trailing Clinton by 18 percentage points in the state.

3. Why is Barack Obama working harder to differentiate himself from Clinton? In a CBS News poll released this week, likely Democatic primary and caucus voters nationwide said they preferred Clinton over Obama by a margin of 45 percent to 25 percent. Edwards drew the support of just 14 percent of the poll’s respondents.

4. Why do Republicans and their talking heads do the juvenile things they do? When the CBS pollsters asked voters to say the first thing that comes to mind when they hear the name “Obama” — other than that he’s running for president — the No. 1 response was some variation of “foreign-sounding name” or “sounds like Osama.”