About 200 people attended One Iowa’s Equality Red Blue Purple event on Sunday in Des Moines. A coalition of more than two dozen statewide organizations, including major labor unions, oppose a constitutional amendment to rescind same-sex marriage rights in Iowa. Republicans as well as Democrats have signed on as co-chairs of Equality Red Blue Purple, and dozens of local organizations have joined the coalition too. After the jump I’ve posted the full list of co-chairs and coalition members.

On Tuesday, supporters of marriage equality plan to deliver “over 15,000 postcard petitions to legislators in every district in the state,” according to One Iowa’s Justin Uebelhor. Opponents of same-sex marriage plan a large rally at the capitol on Tuesday as well.

This week One Iowa’s television ad, “This Place,” will run in the Des Moines market. The ad was created soon after the Iowa Supreme Court’s ruling last April. It depicts marriage equality as consistent with Iowa traditions of fairness and protecting our freedoms under the state constitution.

Click here to donate to keep this ad on the air for an extra week.

Democratic legislative leaders have vowed not to allow floor votes on a constitutional amendment to ban same-sex marriage during the 2010 legislative session. However, Republicans will try various procedural tricks to force a vote on the issue. I expect Democratic lawmakers to stand firm against a marriage amendment, and I hope that they won’t cop out when confronted by constituents who want to ban gay marriage.

On a related note, a lawsuit against California’s Proposition 8, which banned same-sex marriages, goes forward this week in federal court. The lead attorneys are David Boies and Ted Olson, who were on opposite sides during the Bush v Gore case that decided the 2000 presidential election. Writing in Newsweek, Olson laid out “The Conservative Case for Gay Marriage,” which is worth a read.

However, not all advocates of marriage equality support the strategy of appealing Prop 8 in federal court. At Daily Kos, SoCalLiberal laid out the argument against pursuing this lawsuit, favoring an effort to repeal Prop 8 at the ballot box in 2012.