If she was hoping for some level of reassurance from polling released Tuesday afternoon, Sen. Claire McCaskill was disappointed.

The Missouri Democrat barely leads a few challengers and has a split job approval back home, according to a new survey by the Democratic firm Public Policy Polling.

The first-term Senator tops Rep. Todd Akin 45 percent to 44 percent and former state Treasurer Sarah Steelman 45 percent to 42 percent. McCaskill leads attorney and 2010 Congressional candidate Ed Martin 46 percent to 40 percent, and she is ahead of former state GOP Chairwoman Ann Wagner 45 percent to 36 percent.

The margin of error for the survey, which polled 612 Missouri voters March 3-6, was 4 points.

“McCaskill’s leads, even as small as they are, shouldn’t be particularly reassuring for her,” writes PPP pollster Tom Jensen in his blog. “There are at least twice as many undecided Republicans as Democrats in each match up, suggesting that once the GOP candidates become better known they will probably catch up to her pretty quickly.”

It’s worth noting, of course, that McCaskilll failed to earn more than 46 percent in any of the test matchups. That’s certainly not a positive sign for the first-term Senator.

Jensen continued: “Voters really are simply split right down the middle on McCaskill. She’s not unpopular enough to get blown out but she’s probably not popular enough to win easily either, unless Republicans really go off the deep end with their nominee. This is going to be an extremely close race, just like the ones the state saw in 2000, 2002, and 2006 for the Senate.”

The results match an earlier poll showing McCaskill in a tough spot.

As we have reported, McCaskill needs to win over independent voters and some Republicans to match her close victory from 2006.

Roll Call Politics rates this race a Tossup.