Primary elections are not usually very exciting. A few political insiders pay close attention, a few party activists go to the polls and the news media give them a day’s worth of coverage before moving on to bigger and better stories. But Connecticut’s Democratic Party Senate primary was very different. Senator Joe Lieberman’s defeat was a national event, with pundits, candidates and voters across the country speculating for weeks on what it means for November and beyond.

Was this election a referendum on the war in Iraq? Is this a shot across the bow of other incumbents who have put insufficient distance between themselves and the Bush administration? Yes, but maybe it was something more than that. By defeating Lieberman, Ned Lamont became just one of a handful of challengers to beat an incumbent in recent US history. That made this primary an unusual opportunity for voters to affect the outcome of both the election and, presumably, the resulting policies.

In our grossly uncompetitive election system in which nearly 60 percent of Senate seats and over 80 percent of House seats are won by landslide margins of 20 percentage points or more, it’s not surprising that voters jumped at the chance to make a difference. (And they did: Lieberman was only the fourth incumbent senator since 1980 to lose a party primary.) And when the average margins of victory are 21 percentage points in Senate races and a whopping 40 points in House races, is it not surprising that Connecticut was where media from other states turned their attention.

After all, as New York Times columnist Peter Applebome put it, this is a nation in which “rigged redistricting has made genuinely competitive Congressional elections as rare as blowouts by the Knicks.” Consider that in the House, more than 98 percent of incumbents have been reelected in each election since 1998. In the Senate, the average incumbent reelection rate for those four elections is 89 percent. Indeed, 2004 may have been the least competitive year ever, with only five incumbent loses in the House and one in the Senate. (And, needless to say, this isn’t because the electorate is so pleased with the job its legislators are doing!)

For sure, Lamont’s win is a real victory for progressives. But it’s also a victory for democracy. That’s why I keep thinking that the fact that a single incumbent being ousted is cause for this level of attention and excitement reflects the sad reality that most Americans accept and expect entrenched incumbency from elected officials.

It’s not that Americans don’t enjoy cheering for the underdog. They do. More relevant, perhaps, Americans quickly lose interest in a blowout–leading to apathy and declining voter engagement. But last week, something all too rare and exciting happened. As the Times‘ Applebome observed, democracy broke out in the State of Connecticut. Here’s hoping this is just the beginning.