The gubernatorial debate this Thursday at the Garde Arts Center in New London may well be the only one that features all three candidates on the ballot - Gov. Dannel P. Malloy, Tom Foley and the petitioning candidate, Joe Visconti.

That fact alone is raising interest in the debate, which Connecticut Public Television and WNPR radio stations will broadcast live. The one-hour debate begins at 7 p.m.

Whether to include third party and petitioning candidates in these debates is often a difficult decision.

On the one hand, including fringe candidates provides the opportunity to hear differing views and can challenge the major party candidates out of their middle-ground comfort zones. Their participation can definitely spice up a debate.

On the other hand, it can give someone with seemingly no realistic chance at winning equal footing with candidates who do, eating up the time the major party candidates get to respond. On Thursday, for example, all three candidates can only expect to get about 16 minutes each to answer questions, the rest of the time consumed with the questions, introductions and closing statements.

While a debate could go longer, experience suggests a debate running past an hour will not hold the interest of many viewers and creates programming problems for broadcasters.

In setting the criteria for inclusion of third party or petitioning candidates in the governor's race, The Day and its public broadcast partner set the requirement that a candidate had to get at least 5 percent of the vote in a reputable poll. We felt a candidate drawing that level of support could be a factor in what is expected to be a close race.

Alternatively, a candidate could demonstrate broad fundraising support. However, it was poll results that earned Visconti the chance to be on the stage with the Republican, Foley, and the Democratic governor.

When we settled on the criteria, the more likely third candidate appeared to be Jonathan Pelto, a former Democratic lawmaker who has been a big critic of Malloy's education policies on his blog, "Wait What?"

But Pelto's petitioning drive fell short, while Visconti surged, earning his way on the ballot.

Many Republicans feel that is bad news for Foley. Visconti is a Second Amendment advocate who has said he would work to repeal the gun law that was passed in the wake of the Newtown shooting. He is also a strong fiscal conservative. Logic suggests he would draw votes from the Republican. Some conservatives, including tea party groups, have urged him to step aside. It appears he's not budging.

The latest Quinnipiac poll had Malloy and Foley tied at 43 percent, with Visconti moving up to 9 percent, an impressive number for a petitioning candidate with little money for advertising. And, defying the political logic, the poll shows him drawing equally from potential Foley and Malloy voters, yet no one invited Visconti to any of the several debates held so far.

Connecticut NBC affiliate WVIT had asked all three candidates to take part in its Oct. 23 debate, but Foley declined, his campaign unable to come to terms with the TV station over debate rules. WVIT plans to go ahead with a Malloy-Visconti debate.

Tickets are required for Thursday's debate. As of Friday, a few of the free gubernatorial debate tickets remained available at the Otis Library in Norwich and the Groton and Waterford libraries. Before going, you might want to call ahead to make sure any remain.

Congressional debate

On Tuesday, the Garde will host a 2nd District congressional debate between incumbent Democratic Rep. Joe Courtney and Republican Lori Hopkins-Cavanagh. It begins at 8 p.m. and no tickets are necessary. It will air live on WNPR radio, with a delayed telecast Friday at 8 p.m. on CPTV affiliates.

In this case, we did not invite the third-party candidates - Libertarian Daniel Reale and Green William C. Clyde - opening us up to charges of inconsistency. Unlike in the governor's race, however, we saw no evidence these candidates are generating the level of support that could influence the congressional election, in which Courtney is the strong favorite.

The debate process, like politics, is imperfect and prone to controversy.

Paul Choiniere is editorial page editor.