( CNN ) -- Thursday night 's Republican presidential debate in Jacksonville , Florida , sponsored by CNN , will be one of more than 20 such encounters in the past nine months . Beltway conventional wisdom says there have been too many debates . With a slight too-cool-for-school groan and accompanying eye-roll , the argument goes like this : The debates have taken up too much time for the candidates and their campaigns ; they distract from retail campaigning and fundraising ; they give the media too much of a role in the voters ' vetting process . But I take a different view : The debates have been a valuable addition to this election cycle . And two-thirds of South Carolina primary voters seem to agree , saying that the debates played an important role in helping them make up their minds . Expensive television ads , in contrast , seem to have lost some power of persuasion . This is a good thing -- the debates have imposed an unprecedented degree of transparency and accountability on this GOP presidential race . On a debate stage , standing side by side with their competitors , candidates have not been able to entirely hide behind huge sums of money , super PACs , or television ads . They have been judged by the voters based on their working knowledge of policy and their ability to think and speak on their feet . It is a good test of presidential mettle -- and character is revealed as well as intellect over the course of the debates . No one can say that the debates have n't had an impact . Tim Pawlenty probably regrets his premature decision to get out of the race after the Iowa Straw Poll . But it was his failure to repeat a clever line about `` Obamney Care '' to Mitt Romney 's face that caused many voters and donors to conclude that he did n't have the toughness to take on the top job . Rick Perry entered the campaign in August as the savior conservatives were looking for , fulfilling a litmus test checklist of fiscal and social conservative positions that seemed to also resonate with the tea party . In his Texas re-election effort , Perry had stopped talking to editorial boards as part of a pushback on `` media elites '' -- but he could n't avoid the debates . And once in them , he could n't avoid his propensity to stumble over his own tongue . A few epic brain freezes later , Perry 's reputation as a political heavyweight was done . Newt Gingrich 's rise to top-two status is almost entirely due to strong debate performances , balancing Republican red-meat rhetoric with thoughtful policy prescriptions . Yes , it 's true that some his best moments have come when he defiantly pushed back on questions and got the audience loudly on his side , but that was a measure of his ability to connect with voters by voicing their frustrations . He rose from the political dead not with money or organization , but with what he carried into the debates . Mitt Romney succeeded in gliding through the first dozen debates as the de facto front-runner , as other candidates seemed reluctant to take him on hard . He consequently was able to focus his attacks on President Obama -- a strategy that served him well for a while , by reminding the Republican base that at least they had one thing in common with Mitt Romney : a dislike bordering on disrespect for the president . But it was the insistence from other candidates during the debates that Romney release his tax returns that made the Cayman Islands and the `` carried interest '' tax provision subjects of interest during the campaign . And Ron Paul and Rick Santorum 's debate performances have enabled them to attract new supporters , speaking their respective truths to mass audiences they might not have otherwise reached . To top it off , these debates have been widely watched -- by more than 50 million Americans to date . That 's voting with your eyeballs . And even if this presidential campaign has occasionally come too close to resembling a reality show , at least there is a core civic component beneath the conflict . The substance from the debates has driven the campaign news cycle . I understand that for campaign managers and some candidates , a schedule of debate after debate is a hassle that cuts into their fundraising time . They have to study up and learn policy , realizing that they 'll get called out for repeating the kind of bumper-sticker lies they routinely get away with as part of their stump speech . But it 's also the best chance to get their message to the widest number of people -- and that 's what campaigns at their core are about . The fact that there is a risk involved in debates just reflects the real stakes of the race for the most powerful job on earth . Tuesday night 's debate will be the last one for almost a month . February has a few scattered caucuses and primaries , but the next real prize is Super Tuesday in early March . And I expect that voters will miss the debates and the clarifying role they can play . Front-runners will want to avoid the accountability and scrutiny they provide , but it 's a vital chance for voters to judge the candidates directly , adding light to the heat of the presidential primary gauntlet . Follow CNN Opinion on Twitter . Join the conversation on Facebook . The opinions expressed in this commentary are solely those of John Avlon .
John Avlon : Some people in Washington say there are too many debates . He says the debates have played a more important role than paid debate . Avlon says the presidents ' speeches under pressure are revealing .