Former Ku Klux Klan leader David Duke talks to the media at the Louisiana Secretary of State’s office in Baton Rouge, La., on Friday, July 22, 2016, after registering to run for the U.S. Senate, saying “the climate of this country has moved in my direction.” (AP Photo/Max Becherer)

Convicted felon, white supremacist, and former KKK leader David Duke has joined a 24-candidate field vying to replace U.S. Sen. David Vitter, R-La., who decided not to seek re-election.

So, should we be embarrassed?

Assuming that you aren’t thrilled by the former Klansman’s return to Louisiana politics and are being trolled by Facebook friends and family who want to know just what kind of state you are living in, the answer is “Not yet.”

What it takes to qualify to run for the U.S. Senate in Louisiana is a $600 qualifying fee or a petition with the signatures of 5,000 eligible state voters, not fewer than 500 from each of Louisiana’s six congressional districts. For another $300 you can add a party label — Duke is running as a Republican — whether the party likes it or not.

The U.S. Constitution sets three qualifications for service in the U.S. Senate: age (You must be at least 30 years old; U.S. citizenship (You must have been a citizen for at least nine years); and residency in the state you seek to represent. States are forbidden from adding other qualifications for federal offices.

So, the fact that Duke has $900, just turned 66, never renounced his U.S. citizenship and has a P.O. box in Mandeville means that he is eligible to run. It does not mean Louisianians have embraced him. That test is still to come.

So, should we be worried?

If you are enthusiastic about the idea of a U.S. Sen. David Duke, R-La., the answer is that history does not provide a lot of cause for optimism.

You have to remember that Duke has been running for public office in Louisiana since 1975 — 41 years – and has been elected exactly once, to a state House seat from a Metairie district in 1989 — 27 years ago.

He ran for the state Senate in 1975 and 1979 as a Democrat. He ran for president in 1988 as a Democrat and in 1992 as a Republican. He has run for the U.S. Senate twice before — in 1990 and 1996 — and ran for the U.S. House in 1999.

Duke finished second to incumbent U.S. Sen. J. Bennett Johnston in the 1990 open primary when the leading Republican pulled out in an effort to deny Duke a spot in a runoff against the vulnerable Johnston.

But Duke did make a statewide runoff a year later in what proved to be the peak of his political career: a high-profile, one-on-one showdown with ethically challenged Edwin Edwards that gave Duke national publicity.

Duke ended up losing in a landslide with 39 percent of the vote to Edwards’ 61 percent in what became known as the “Vote for the crook, it’s important” election.

As it turned out, both Edwards and Duke would end up being “crooks” convicted of felonies. Edwards for manipulating the state’s gambling license process and Duke for ripping off contributors.

So, how can a convicted felon run for the U.S. Senate? Is that a Louisiana thing?

As noted above, the U.S. Constitution has only three requirements for eligibility: age, citizenship, and residency.  It is up to the Senate (or the House) to decide whether a member is qualified to be seated when a challenge is raised.

For the record, Duke pleaded guilty in 2002 to mail fraud and filing a false return.

He was accused of telling supporters that he was in bad financial shape and at risk of losing his Metairie home and all his savings.

In fact, The Times-Picayune reported at the time, Duke “voluntarily sold his home for a profit” during the period in question — 1993 to 1999 — and moved to Mandeville, held investment accounts that “at times contained substantial sums of money” and spent much of his fund-raising proceeds at casinos in Mississippi, Las Vegas, and the Bahamas, prosecutors said.

Duke was sentenced to 15 months in federal prison, serving his time in 2003 and 2004.

So, does Duke have a chance of getting elected?

Keeping in mind the caveats raised above, Duke does have an advantage with name recognition. He obviously is hoping to recapture the lightning he caught in 1991 when he emerged from a crowded field — 12 candidates — to make the runoff.

One theory of Louisiana’s open primary system is that it tends to favor those at the polar ends of the political spectrum, matching the most liberal and the most conservative in the runoff.

In a field of 24 candidates — including some who are well-known and well-funded — Duke may be calculating that getting 10 to 15 percent of the vote primarily on his existing name recognition could be enough.

Given that the Republican Party has already condemned and disavowed him and that business and civic leaders will do the same — think about landing the 2017 NBA All-Star Game with Sen. Duke in the welcoming party — it seems almost impossible to think that Duke could win the Dec. 10 runoff.

One complication that political reporters and observers are already starting to mull is the idea that the Louisiana seat — the last one to be decided because of Louisiana’s open primary system — could decide who controls the Senate.

Then we can return to that question of whether to be embarrassed.