Late last month, when Sen. Mary Landrieu (D-La.) disclosed her block of a Senate vote on the planned mayoral takeover of the D.C. public schools system, she was making what has become something of a signature move for her — employing a rare procedural tactic to leverage her agenda.

It’s not so much her use of the hold — on the schools bill and several other items in recent years — that is helping earn Landrieu a noteworthy reputation in the Senate. It’s the fact that the moderate Louisiana Senator isn’t secretive about it and, more often than not, even advertises her efforts to stall legislation to push her priorities.

“I don’t do them often, it’s kind of a last resort, but my view is if you don’t overdo it and do it for really important matters, it can be effective,” Landrieu said in a recent interview.

Landrieu has issued holds while serving in both the majority and minority and seemingly without discrimination toward Democratic-backed bills or Republican ones. In the case of the D.C. schools bill, Landrieu was heeding the concerns raised by D.C. Board of Education President Robert Bobb, a move that ran counter to the will of another Democrat, Mayor Adrian Fenty.

In that instance, Landrieu — while initially quiet about her hold — quickly came clean, arguing she wanted more time to review the legislation. She later lifted the block.

Many of Landrieu’s Senate holds in recent years have been used as leverage points to secure aid and attention for her Hurricane Katrina-ravaged home state. Last year, Landrieu sought to hold up scores of President Bush’s executive nominations unless and until he agreed to offer more money to rebuild levees damaged by the storm.

In April, Landrieu blocked Senate confirmation of Lt. Gen. Robert Van Antwerp to head the Army Corps of Engineers until he visited the Gulf region. Van Antwerp did, and Landrieu soon removed her hold on the nominee.

“Now my colleagues know when I sit down at the desk there’s no way to get me out of it,” Landrieu said. “I don’t do it unless I absolutely have no choice.”

Landrieu’s approach is relatively unusual in a Senate that still relies on the secret legislative hold, where lawmakers regularly turn the other way to avoid taking credit or fessing up to the use of the maneuver. Senators sometimes even go as far as employing what’s become known as a rolling or rotating hold, or passing a secret hold around from Senator to Senator to avoid being discovered.

One of the more recent hold capers to befuddle the chamber came on a measure requiring Senators to file their campaign finance reports electronically. To this day, no Senator has come forward to admit being the original blocker of the bill.

Unlike some of her colleagues, Landrieu said she doesn’t see the value in keeping her legislative holds confidential. Rather, Landrieu said she believes she can be more successful by declaring her target.

“Holds can be effective when used appropriately — if they aren’t overused and they are disclosed publicly,” she said. “And you have to substantiate it.”

And while many Senators laud Landrieu’s tenacity, those whose interests or agendas fall prey to the holds aren’t always so admiring.

“There are Senators who choose what legislation to hold, and then there’s Sen. Landrieu who chooses what legislation to let through,” said a GOP Senate leadership aide.

“At certain times it’s been a headache for both leaders,” a senior Democratic Senate staffer acknowledged. “But you’ve got to give her credit for fighting like hell for her state.”

Indeed, one White House aide acknowledged recently that “she’s been pretty effective at it,” and rarely digs in her heels to a point where she is unwilling to look for a compromise to loosen the grip.

The Van Antwerp hold was one example of that, as was Landrieu’s well-publicized move last May to hold up the nomination of now-Interior Secretary Dirk Kempthorne. Landrieu stopped Kempthorne’s confirmation until she felt she had won adequate assurances from the White House to keep focus on Gulf Coast flood protection and coastal restoration.

“Public holds are really the only way to be effective,” Landrieu said. “I think when you put a hold you have to have a strong enough reason to discuss it publicly and for it to stand the sunshine.

“I don’t understand the secret hold,” she said.

The procedure continues to be one of the Senate’s most controversial maneuvers — with Senators in both parties favoring and opposing them. It is even a focus in the pending ethics reform package, which carries a provision requiring Senators take credit for their holds within three days of notifying leadership.

Landrieu said that while some holds “can be nasty,” they also can be amicable and, in her case, “are not personal.”

“It’s all about policy,” she said. “It’s about leveraging to gain something.”