Civility — respect for the opinions and needs  of others — is a requisite for a healthy democracy. Unfortunately, it is in short supply in the United States, and our nation’s leaders deserve a good portion of the blame.

Exhibit one: The 2012 presidential campaign has been ugly on both sides. The numbers tell us that more than 70 percent of the ad money has gone to negative messaging. In one 14-day period in July, 90 percent of the ads criticized their opponent.

Another set of numbers gives us a related narrative: Americans see the lack of civility and don’t like it. They believe it is hurting the country and the tone is being set by our leaders.

Two-thirds believe that candidates spend more time attacking their opponents than addressing issues; 80 percent are frustrated by the tone of the political discourse; and 64 percent believe the negative campaigns harm the political process. That’s just background. The central points are that almost two-thirds believe this country has a larger civility problem and nearly 70 percent think that politicians have a negative influence on how people get along.

Exhibit two: At the beginning of the school year, the Chicago Public Schools (CPS) were closed for the first seven days of the academic year. The reason: a teachers’ strike that followed ten months of negotiations between the mayor and the teacher’s union.

To put the magnitude of the work stoppage in perspective, here is more about CPS.

It is the nation’s third largest system. It  enrolls 350,000 students, employs 26,000 teachers and support staff, and operates 578 schools. Almost 90 percent of the students come from families below the poverty level. The high school graduation rate is 60 percent. On the National Assessment of Educational Progress test (the nation’s report card), of CPS’s eighth-graders: Only 26 percent scored proficient or better in math; only 23 percent scored proficient or better in reading; and only 7 percent scored proficient or better in science.

The strike received national attention. Politicians at all levels weighed in.  Newspapers ran front-page articles and published editorials. The Internet, television and radio covered it extensively. Three stories emerged and were repeatedly explored, discussed and analyzed. The strike was a long-anticipated showdown between labor and management. The strike was a test of strength between factions within the school reform movement. The strike was part of the ongoing national battle (with a few interesting twists) between liberals and conservatives, Democrats and Republicans.

Here’s what’s wrong with this picture: Sadly, few in the political, policy or media worlds talked about the tragedy of children, primarily poor children, being locked out of the classroom. The needs of the students were treated with dismissiveness. While the leaders argued about compensation, health benefits, teacher evaluations and job security, students lost precious learning time. Both sides say the lost days will be made up, but no one yet knows how or when.

Coincidentally, on the second day of the strike, the Organization for Economic Cooperation and Development issued its 2012 Education at a Glance report. (This analyzes and compares educational achievement in approximately 30 countries.)

Here is one of the major findings: “In Italy, Portugal, and the United States, young people from families with low levels of education have the least chance of attaining a higher level of education than their parents.” In other words, when we fail to serve our students, the chances are that we visit that same failure on their children. In Chicago we may have harmed not one, but two generations.

This lack of civility is hardly new in America. There have been times in our history when elected officials have literally come to blows with one another. But the modern world has altered the dimensions of the problem. And the reason is technology. Lack of civility was once between individuals or among smaller groups. For the most part, it could be contained. Not so anymore. Messages can be sent to millions instantaneously. Virtually anyone can initiate or receive the information. And anonymity is easily kept.

Many of us were told as children that “sticks and stones will break my bones, but names will never hurt me.” We should retire this saying. Unless our leaders rein in their rhetoric and start acting with consideration toward others, we run the risk that we will all follow their lead.  If that happens, the civility that binds will be replaced with the lack of civility that divides.