"Congress shall make no law respecting an establishment of religion, or prohibiting the free exercise thereof; or abridging the freedom of speech, or of the press; or the right of the people peaceably to assemble, and to petition the Government for a redress of grievances."
First of all, I am not Congress and I have passed no law. The first amendment is directed toward government, not individuals, companies, media entities, etc.
Secondly, nowhere in the first amendment does it say that you have a right to air your opinion on my blog, my newspaper, my television show, or any other speech outlet that I choose to employ. Nor does it say you (or I) have a right to be heard. Your right under the United States Constitution is to express yourself via your own means. You have a blog and I cannot and will not make any attempt to stop you from writing whatever you want on it. If you don't have a blog, start one -- they're free. My blog, however, is mine. I can, have and will delete comments that I find disagreeable. I don't even have to have a good reason.