Sen. Mary L. Landrieu, D-La., and her top 2014 opponent, Rep. Bill Cassidy, R-La., are in a de facto race to pass competing flood insurance legislation pending in both chambers.

As one of this cycle’s most vulnerable incumbents, Landrieu has emphasized her seniority in her re-election. She’s argued it makes her a powerful voice for Louisiana in Washington — powerful enough to convince leaders to push forward flood insurance extension.

For Cassidy, getting enough support for the flood insurance bill would demonstrate an ability to put his state above the conservative politics that often drive the House GOP. Disaster relief, even though historically bipartisan, has proven to be a lightning rod over the past few years, with a near-revolt among GOP ranks over a delayed Hurricane Sandy relief bill in 2012.

Senate leadership aides noted the urgency with which Landrieu has been pushing the bill. It’s not only good for her from a policy perspective — Louisiana politicians regardless of party don’t want to see premiums increase — but also to prove her political might within the chamber. Landrieu is also in line to be chairwoman of the Senate Energy Committee.

Leaders had agreed to move onto the bill last week, when they assumed Republicans would block  an unemployment insurance extension. Landrieu had even scheduled a press conference, which was led officially by others to avoid giving Senate Republicans an opportunity to filibuster a “Landrieu bill”. But that effort was stalled when the Senate unexpectedly voted to end debate on UI extension bill.

“This is not about Mary Landrieu, Bill Cassidy or the Senate race. This is about helping people in a desperate situation,” Landrieu told WWJ radio in Louisiana last week, as reported by the Times-Picayune in a story about the Cassidy-Landrieu dynamic on the bill.

An aide to Landrieu told CQ Roll Call there’s “no significance to the Senate moving first, other than that there is more support for the legislation right now in the Senate.”

Meanwhile, in the House, a GOP leadership aide says doing the flood insurance legislation has been a priority for the caucus since the fall. The aide noted Cassidy’s bill had appeared repeatedly on Majority Leader Eric Cantor’s Powerpoint presentation to rank-and-file members on the party’s agenda in closed-door meetings.