It's difficult to give specific advice without knowing the actual traffic level(1) and type of ads and placements(2) you have on your website but I'll make the assumption that those visitors don't record visits of extraordinary length resulting in at least several hundreds of thousands of pageviews/month.

In this case, your best bet would be to sell your ad space in a tenure model (per month, for example) as opposed to CPM or another, less advantageous pricing model. This would ensure you're covered for any traffic fluctuation, don't have to deal with monetizing remnant inventory, and usually translates in higher eCPMs overall.

Tip: offer campaign features not usually associated with smaller publishers, as a strategy to stand out. For the Politics vertical, I'd suggest looking into a guarantee that no competing campaigns would be displayed simultaneously (you can do so in pretty much any ad server out there).

(1) pageviews, ad impressions
(2) number of ad placements, sizes, location, type of ad creatives

Do you have direct advertisers now? A company like BuySellAds or RubiconProject offer a good intermediate step through their marketplaces for premium advertisers.

With 30k uniques in a specific vertical, you should receive decent rates.

We manage the traffic to just over 1 million domains for clients and from experience I would head down the either of three routes:
1. Park the domain - you should get around 20RPM or about $800/month in revenue. This is an easy solution but destroys a lot of the value in the website.
2. Sell the spots to advertisers on a monthly basis. I do this with my own blog and make around $30K/year with little effort.
3. Insert video and other advertising into the website. You'll probably max out around 15RPM but you maintain the sites presence.

I hope that this helped you out.