I have written before about how you cannot prepare for a serious court proceeding using just the resources you find on the “free” web. (And, aren’t all court proceedings serious?)
That is, if you have an adversary who knows how to research law and legal procedure, if you will appear before a judge in a court of record (as opposed to, e.g. a small claims court or traffic court where you are not expected to know “the law”), if you want a fair shot a winning your case, then:
You need to do the research – and that means researching case law and statutes, And, that is just the BEGINNING:
(And, even in small claims and traffic court it helps to do your research.)
As I’ve also said before, ad nauseam, “if you read only what is written in the statutes, the cases, and the constitutions you will be absolutely wrong about what the law is.”
Now, about that Oregon case law research:
1) Oregon Cases: Last, or first, or wherever, you’ll need to look at Oregon case law on the subject of petition signatures. You can use the print Thomson-Reuters Oregon Digest (see also bibliographic info at the Open Library), which you’ll find in any Oregon law library, or you can use an online legal research database, e.g. Casemaker, Fastcase, Lexis, LoisLaw, Westlaw, etc.
2) You can also use the free or low-cost legal research database links in this blog’s sidebar (and more about free legal databases), but a lot of the free sites have case databases that contain only the most recent 10 years of case law. A lot of legal research relies on cases older than that, so you either need to know what you are doing or ….
3) You will need that database or that Oregon Digest. You cannot do thorough case law research “on the web” using a general search engine. You will need a database that is full-text, indexed, and preferably comprehensive with Oregon case law back to at least the 1920’s, if not earlier. The Oregon Digest indexes Oregon cases back to 1843.