I am building a blog for myself. Because it is relevant, here is the link: http://www.codetunnel.com. As you can see the page loads via AJAX so that I can do some stylish loading effects, among other things. It's actually a web-terminal that accepts commands and arguments and processes them via ajax; my URL structure executes these commands based on the URL passed in so that different pages can have unique URLs even though they are loaded via ajax. I've done past projects like this but have never cared much about optimizing the site for search engines, until this one.
Would a blog post being loaded via AJAX hurt its ability to be found by web crawlers? I'm assuming it would but I want your opinions before I decide how to move forward.
It depends. If you use unobtrusive javascript and progressive enhancement meaning that in your page you have links:
@Html.ActionLink("foo bar", "foo")
which would be AJAXified in some external js file, web crawlers will follow those links as all normal links and if the server returns content this content will be indexed just as all other content of your site. But if the url is built with javascript, then, no, it won't be indexed as crawlers normally do not execute javascript. I would also recommend you providing a sitemap as well.