Another poll on Louisiana's U.S. Senate race shows it's a tight race between Democratic incumbent Mary Landrieu and Republican U.S. Rep. Bill Cassidy.

The Rasmussen survey of 750 voters has Landrieu leading Cassidy 46-43 percent.

Political Analyst Clancy Dubos is not surprised by the poll numbers.

"It's going to be a typical Mary Landrieu race," Dubos said. "It's going to be hard fought. There's going to be a lot of charges and counter-charges going back and forth. It's a classic Louisiana showdown."

Public Policy Polling also released a survey this week that showed a tie between Landrieu and Cassidy in a likely run-off.

It's a classic Louisiana showdown.

Dubos says what motivates a voter could decide this race. He says voters who care about national issues, like the Affordable Care Act, will vote for Cassidy, and those who support Landrieu's clout in the Senate will vote for her.

"She's a committee chair, presiding over a committee (Senate Energy and Natural Resources) that's very important to Louisiana's economy," Dubos said. "Those who look at it through a Louisiana prism, tend to lean towards Landrieu."

Republicans Rob Maness and state representative Paul Hollis are also running, but they were not included in this poll.