Either of these forms would be grammatically valid, but (in general) I would not use them:

>    I support the idea that...
>
>    From my perspective, I support the idea that...

In my English writing classes, we were specifically taught to remove these types of phrases, since they serve no purpose.  They only make your position sound weaker.

Obviously you are the person writing (or speaking) the sentence, so we already know that it's your perspective, and that you support the idea.  :-)