By Randy Hammons

The Daily News

The race for one of Louisiana’s U.S. Senate seats could be one of the most hotly contested in the state by the time the Nov. 4 primary election rolls around.

Incumbent Sen. Mary Landrieu, D-La., is asking Louisianans to return her to Washington, D.C., for a fourth term.

Landrieu’s top challenger in the race so far is Rep. Bill Cassidy, a Republican. Republican retired Air Force Col. Rob Maness is considered a dark horse, but Maness, R-Madisonville, could split the vote between himself and Cassidy. He is a Tea Party favorite.

Other candidates who qualified include Democrats Wayne Ables, Raymond Brown, Vallian Senegal and William P. Waymire Jr. Environmental activist Thomas Clements is running as a Republican. Brannon Lee McMorris is running as a Libertarian.

Louisiana has what is known as a “jungle primary system,” which means candidates of all parties will appear on the same Nov. 4 ballot. Unless one candidate wins more than 50 percent of the vote in the first round, a runoff election is held between the top two candidates, who may be members of the same political party.

Landrieu has won in runoffs in two of her three Senate elections, but her support of President Barack Obama on a number of issues apparently has hurt her in some quarters.

Landrieu ardently supports Obama’s Affordable Health Care Act, or ObamaCare, as it is widely known. But she makes her differences with the president readily known when it comes to the state’s energy industry, including the hot-button issue of the Keystone XL pipeline. She chairs the Senate’s Energy Committee.

“I am such a strong supporter of the Keystone XL pipeline and have been for many years,” Landrieu told Fox News. “It is not my clout. It is Louisiana’s clout. Let’s not give it up.”

Cassidy is a physician and a two-term member of Congress. In May 2013, Cassidy introduced the Energy Relief Act of 2013. The bill required the Environmental Protection Agency to submit reports to both the Congress and U.S. Department of Energy regarding proposed regulation that would have significant compliance costs.

Cassidy was a vocal opponent of the Affordable Care Act. Citing his medical background in a state-run public hospital, Cassidy argued that Obama’s heath overhaul would not lower costs and would give too much decision-making authority to the federal government.

Maness recently said he would end the dysfunction in Washington because he would vote in the best interests of the country.