Blogger is just a platform for individuals to write and create content. Under U.S law, neither Blogger or it’s owner Google are liable for damages as a result of defamatory comments created by others.

If you want you can read the official documents here. Section 230(c) of the Communications Act doesn’t just apply to blogs but also to web search results and any re-publisher who is not the original author.

Here are your options:

1. Contact the website owner/author and ask for the comments to be removed.
2. Take legal action against the site owner/author.
3. Consider filing a DMCA request if someone has violated your copyright (perhaps copied your text or stolen your photo), also consider filing a separate request for Google web search if the blog is showing up in the search results.
4. Impersonation is different from defamation and yes, you can ask Blogger to remove a blog set up to impersonate you.
5. Hateful material “toward groups based on race or ethnic origin, religion, disability, gender, age, veteran status, or sexual orientation/gender identity is not allowed on Blogger”.  See this page.

Other Options

As most re-publishers (Google, Bing, Blogger etc) are not liable for any losses as a result of third party defamation, they do not accept requests to remove it.

If you cannot find any other way of getting the comments removed (copyright claim, legal threat etc) then consider engaging in “reputation management”. This is the process of creating positive content on friendly websites that will appear in search engine result pages.

The idea is to “crowd out” or nudge down negative web pages so they are not seen.

Many large companies engage in online reputation management and nowadays it is becoming popular with individuals too.