We can't give up on communication... even with those that we disagree with the most. The "other side" may not listen to what we say anyway, but they certainly won't listen if we refuse to listen to them. The purpose of a debate is not necessarily to win over the opponent but rather to influence those who are merely listening.
It doesn't matter if the issue is 2A rights, the economy, unemployment, management of natural resources, or government spending - it's pretty well understood how the true conservatives will vote, how the socialists will vote, how the liberals will vote, how NRA members will vote, and so on. Our goal should extend beyond preaching to the choir. We MUST influence those in the middle, the centrists. Whether we like it or not, those are the folks who decide elections. And once elected, it's often the centrist legislators who pass, or block, important legislation that impacts all of us.
Spokesmen for a cause, any cause, who take the "in your face - no compromise" approach do a wonderful job rallying those who already believe. And this is critical for fund raising and turning out the vote. It isn't as effective, however, for positively influencing those who are undecided or those who view a partcular issue as secondary. Those who are undecided on an issue want to hear the debate, the dialogue, the reasonings and justifications for a position. To reach these people, we must be willing to communicate. We must offer the promise of an open mind. And we must present ourselves and our arguments in a palatable fashion.