Republicans have jobs and responsibilities. We can’t afford to stay out all night at some smelly bar. Our family’s depend on us to make it to work the next day and actually be productive.
This survey was in DC, so there's not going to be much of a difference, education and job-wise, between Republican and Democratic bar patrons, at least in the areas these guys looked at. They all have to get up the next day and work some pretty demanding jobs.
Everyone in politics in DC, whether Republican or Democrat, drinks and schmoozes heavily. Well, except for the boring fundie staffers or the stuck-up ultra-left winger do-gooders. But who wants to hang out with them?
Go to any bar in DC near the Capitol or White House and you'll see a bunch of staffers, Republican and Democrat, drinking, gossipping and flirting. That's how this town works- it runs on booze, gossip and BS.