As anyone who follows my tweets and blog posts knows, I’m a fan of MSNBC’s “Morning Joe.” But as they kick off their 5-year-anniversary week, it’s perhaps appropriate for some unsolicited advice. (Just as Joe Scarborough offers Mitt Romney intellectually honest analysis regarding problems in his campaign, I will attempt to do the same.)

In the past year, the show has drifted leftward. This is unfortunate — and potentially costly. Many center-right viewers find “Fox & Friends” vapid, so they flip over to MSNBC (until things get out of hand around mid-morning). But there may come a tipping point where they are associated with the rest of MSNBC’s liberal brand. Their enviable role as an opinion leader both sides have to pay attention to feels tenuous — but I’m not sure they realize it.

(The nadir was, perhaps, Chris Matthews‘ decision to berate RNC chairman Reince Priebus on the program during the RNC convention in Tampa.)

The leftward trend seems to coincide with the departure of Pat Buchanan — who had been a show regular. In fairness, Joe and co-host Mika Brzezinski both publicly objected to his exit from the network, but he hasn’t really been replaced. (The notion that Steve Schmidt could provide balance is indicative of the the worry that they don’t get it.)

To be sure, Buchanan wouldn’t be confused with being a mainstream conservative, but he was an intellectually honest conservative observer, as well as a skilled and seasoned debater. And because he was a regular on the show — and due to his experience and knowledge — Buchanan was often able to push-back against the “conventional wisdom” of liberal elites.

It’s hard to quantify the impact Buchanan had on the show — or to describe the philosophical vacuum that has existed since his exodus. With Scarborough and Buchanan both regularly on the show simultaneously, the dynamic was certainly different.

To call the selection bias associated with “Morning Joe’s” recent guest booking evidence of overt liberal political bias would be simplistic. “Morning Joe,” it seems to me, is most interested in booking establishment elites or insiders. These elites, of course, just happen to be liberals. Cultural bias is more insidious than overt political bias. For casual viewers, this is a distinction without a difference.

It would be a mistake for the show to attempt to overcorrect by bringing in conservatives who don’t fit the show’s culture (most of these people already have Fox News contracts, anyway.) There are certainly many things about the show that works terrifically.

But there are plenty of legitimate conservatives who would fit into the milieu — while simultaneously helping provide balance. I could name twenty people who might be a good fit (the fact that I could — and they probably couldn’t — is again evidence of a problem.) Note: I’m not advocating for a “diversity” hire in the name of fairness. The show (and their viewers) would benefit from having someone around who has a different worldview.

This problem is easily fixed.

Why do I care? Bad shows don’t necessitate commentary. They don’t deserve it. But because “Morning Joe” is an important show, it warrants constructive criticism.

Let’s hope their next five years are more like their 4th year than their 5th.