In the Republican Party’s one real shot at knocking off an incumbent Senate Democrat, Louisiana Treasurer John Kennedy is running almost even with Sen. Mary Landrieu (D), according to a new poll conducted exclusively for Roll Call.

Landrieu led Kennedy 46 percent to 42 percent, according to a survey of 643 registered voters completed earlier this week by Survey USA, an automated polling firm. But the margin of error on the poll was 3.9 points, putting the two candidates in a virtual dead heat.

According to the poll, Landrieu, who is now in her second term in the Senate, was viewed favorably by 40 percent of Louisiana voters and unfavorably by 32 percent.

Kennedy, a former Democrat who jumped to the Republican Party before winning his third term as state treasurer this fall, is viewed favorably by 35 percent of voters and unfavorably by 10 percent. Of those polled, 56 percent had no impression of Kennedy or had not heard of him.

Although Kennedy entered the race in late November, it had long been expected that he would challenge Landrieu. And in searching for barometers of the potential matchup, Republicans and Democrats were quick to latch on to two different results from the state’s constitutional officer elections this past fall.

In his election, Rep. Bobby Jindal (R) was able to win the gubernatorial race outright with 54 percent of the vote on the first round of balloting, which GOP operatives have interpreted as a sure sign of an increasingly Republican electorate in Louisiana.

But in his race, Landrieu’s brother, Mitch Landrieu (D), won re-election to his lieutenant governor’s post with 57 percent of the vote, which Democrats were equally quick to tout.

Interestingly, according to the Survey USA poll, 67 percent of those who voted for Mitch Landrieu in October said they would vote for Mary Landrieu, but 23 percent said they would cross over and vote for Kennedy. Meanwhile, of those who voted for Jindal for governor, 61 percent said they would vote Republican in the Senate election and 30 percent would vote Democratic.

Kennedy led among white voters by 22 points while Landrieu led by 60 points among black voters. Kennedy also led by 12 points among men while Landrieu led by 19 points among women.

Landrieu raised $857,000 for her campaign in the third quarter of the year and reported $3.3 million in cash on hand as of Sept. 30. Kennedy won’t have to file his first Federal Election Commission report until the end of January.

The increasingly large target on Landrieu’s back stems from her close winning percentages in her two previous elections (52 percent in 2002 and 46 percent in 1996) and her state’s conservative bent (President Bush carried Louisiana with 57 percent in 2004).

In addition, conventional wisdom suggests that Landrieu’s base in minority-heavy New Orleans has eroded in the aftermath of Hurricane Katrina.

One other issue that could have some impact on the Senate election was just beginning to play out in Louisiana when the Survey USA poll was taken. That’s the Dec. 7 retirement announcement of 11-term Republican Rep. Jim McCrery.

McCrery is the ranking member on the powerful House Ways and Means Committee and a strong fundraiser for the party. His impending retirement set off wide concern in state newspapers and in Louisiana political circles that the party was losing its seniority and clout in Washington, D.C.

In recent years, the state has seen a decline in its sons and daughters in Capitol Hill leadership posts after men like former House Appropriations Chairman Bob Livingston (R), former House Energy and Commerce Committee Chairman Billy Tauzin (R) and former Senate Democratic Chief Deputy Whip John Breaux left Congress.

This week, Breaux acknowledged the mounting concern in the state.

“Seniority is important, it’s something the South and Louisiana in particular has always understood,” Breaux said.

And that concern could play into the hands of Landrieu, who currently chairs the Senate Appropriations Subcommittee on the Legislative Branch.

“It helps Mary because people are saying ‘look, Mary is becoming senior and this would be her third time in the United States Senate and we don’t want to replace her … especially when we’re losing these others, even though it’s in opposite parties,’” Breaux said. “I think Mary would actually be enhanced by the argument of ‘don’t lose all our seniority in such a relatively short period of time.’”

But two-term Rep. Charles Boustany (R-La.) said this week that he believes the concern over Capitol Hill seniority that has developed since McCrery’s announced his retirement is “more of a knee-jerk reaction.”

Shortly after the 2004 election “everyone was decrying the loss of seniority,” Boustany said. “Look at what our delegation has passed since ’04, especially since the hurricane … I think it’s a question of how to be effective.”

The Survey USA poll also asked Louisiana voters for their views on various Congressional leaders and found that Speaker Nancy Pelosi (D-Calif.) had a minus-15 net favorability among those polled, Senate Majority Leader Harry Reid (D-Nev.) had a minus-13 net favorability, House Minority Leader John Boehner (R-Ohio) had a zero net favorability and Senate Minority Leader Mitch McConnell (R-Ky.) had a plus-one net favorability.

Congress had a 21 percent approval rating overall in Louisiana while President Bush had a 32 percent job-approval rating in the state.

Immigration was the top issue that Louisiana Republican voters wanted Congress to focus on, according to those surveyed, while Democrats wanted Congress to focus on health care.