If you aren't registered by today, you can't vote in the Primary on March the 5th.
This is for California only, BTW.
You can register at the DMV, or even the Post Office in most cities.
One vote can make a difference. If you don't believe that, ask the people of Florida whose votes were hand counted.
Don't buy the JW line of not getting involved. It's where you live. Take one hour and get informed on the issues and choose the person who best represents your interests.
Lisa