Here's an interesting thought experiment.
Find a liberal and engage them in a political discussion. Explain that you are a conservative, and that you are in favor of a balanced budget, the same tax rate for everybody and no loopholes for anyone, including the rich. Ask them their position on government spending.
Then, ask them what they think of your opinion. If they are open-minded and have listened, you may have made a breakthrough with them. You won't agree on everything certainly, and you shouldn't. But you may have someone with whom you can engage in both debate and discussion and find common ground with. If they see you as a social Darwinist or just clam up and stop engaging you, you have gained some insight into how you are perceived. Does it help? Not really, but it does clarify things for you.
In the case where they start to perceive you as slime, the obvious follow up question, is why they think of you that way. You can cite family, friends, your community involvement and explain that you are a good person with a different view on how to do the greatest good for the most people. Watch and see if their head explodes.