America is a diverse place so should have representation from all groups. This has become a reality now for minority groups such as Muslims, homosexuals, and Hindus when most of these groups were(and often still are) demonized by the general American populace. Let's keep it going and hope America elects a Sikh next!
The election of the first openly gay Senator is a big deal. It shows how America is changing. Ten years ago an openly gay senator would never have won an election. This is significant because it opens the door for future openly gay candidates to run. It also shows the way Americans think nowadays is very different, not nearly as many people judge someone for their sexual orientation.
I believe that the election of Tammy Baldwin as our first openly gay U.S. Senator is extremely significant for America because it is always a giant step forward socially when we get past our insecurities and prejudices to provide more people with their rights and not discriminate against anyone for any reason.
This election shows how far gay and lesbian people have come in the eyes of the American public. It is not the case so much anymore, outside of the religious right, that these people are feared, ostracized and judged for being who they are and who they love. More and more, this is changing, and the country is becoming more tolerant towards them. This is but another example of that.