I've been to both, and while Portland Maine has a surprising number of breweries for its size, Portland Oregon had way more. A quick google search confirms Portland OR has more than twice as many as Portland ME.
If you include the Portland OR metro area, it has more breweries than the entire state of Maine.
That may be but Portland, Oregon has some excellent cider as well. Belmont Station in Hollywood is pretty much my go to place, they've a diverse selection of beer and cider.
To be clear Belmont Station has both a bar (biercafé in hipster speak) and a store. The store has a really great selection of both beer and cider. My favorite is Reverand Nat's sour cherry — self-described as more of a lambic beer than a cider.
Their selection of California stuff isn't quite up to snuff but they carry 2 Towns as well — a friend had explain that reference to me.
There are more breweries learning how to do good lagers but still few and far between.