More background on this race can be found in my previous diaries here or at the Iowa progressive community blog Bleeding Heartland.

A little more than two weeks before the Democratic primary in Iowa's third Congressional district, Ed Fallon has challenged Congressman Leonard Boswell to shift his support as a superdelegate from Hillary Clinton to Barack Obama.

It's a shrewd move for several reasons.

First, Iowa's third district went for Obama in January, as today's press release from Fallon underscores:

Fallon says, "Even though Hillary Clinton finished behind Barack Obama and John Edwards in the Third Congressional District, Congressman Boswell continues to ignore the will of the majority by saying he will cast his superdelegate vote for Clinton."

Fallon worked with John Edwards through the Iowa Caucuses and then endorsed Barack Obama in February. Fallon says, "Both Obama and Edwards are people whose principles reflect my belief that we need to get big money out of politics and stand up to the special interests to accomplish real change in this country. It's time to come together and focus on defeating John McCain in November."

Most of the Iowa Democratic Party establishment is backing Boswell (including many of Obama's high-profile endorsers). However, the activists who are strong Obama supporters clearly lean toward Fallon.

As I've written before, Fallon yard signs are often seen in the same yards as the Obama "HOPE" signs, while Boswell's yard signs are frequently paired with Hillary signs. Just last weekend I was with a friend who has both the Obama and Fallon signs in her yard on a busy corner. She was an Obama captain in a large Des Moines precinct. Her job takes her to many neighborhoods in the metro area, and she told me she hasn't seen any yards with signs for HOPE and Boswell (I have heard of a couple of those) or yards with signs for Fallon and Hillary (I have seen that combination only once).

Any further publicity that aligns Fallon with Obama, and Boswell with Clinton, can't hurt the challenger and may even sway some undecided Democrats.

Second, Obama is coming back to Des Moines this Tuesday for a victory rally on the night when he is expected to win a majority of the Democratic Party's pledged delegates. This will surely be a big media event.

Fallon spoke at a Nation for Change rally supporting Obama in Des Moines last month. Although Fallon will probably not be able to address the crowd this coming Tuesday, Obama's visit may generate some media coverage about which prominent Iowans are supporting Obama, and which are still with Clinton.

Third, since Boswell has rejected all invitations to debate, Fallon will not have many more opportunities to trip up the incumbent before the June 3 primary. Today's challenge is a way to shift the media narrative toward a subject less favorable to Boswell.

Speaking of debates, Boswell has said he could not spare the time for them because he is too busy working on the farm bill and other legislation. But Congress has already sent the farm bill to President Bush and is likely to be in recess during the last week in May. It's too bad that Boswell can't be straightforward about his reasons for not debating Fallon.

A final note before I end this post: after trying for more than a week, I have so far been unable to get any comment from Boswell's campaign or his Congressional office on whether Boswell was the Democrat on the House Intelligence Committee who on May 8 supported a Republican effort to add the Senate version of the Foreign Intelligence Surveillance Act (which includes retroactive immunity for telecommunications companies) to the fiscal 2009 Intelligence authorization bill.

I am still trying to get someone who works for Boswell to confirm or deny this speculation and will bring you up to date on this in my next post on the IA-03 primary.

Meanwhile, I welcome your comments and questions.