Looking at a national scale is ridiculous because the scope will change completely depending on geography and other factors, even if they don't know about law schools explicitly. If I had to say the national rank, lay prestige for the common person who knows nothing about law, in the t14 schools will kind of run like this:
1. Harvard - Harvard law is just way overplayed in the media. Undergrad yale/harvard is a wash but law... The big h for sure
4. Columbia - Ivy league, fancy sounding name. That's all people need to know.
5. Cornell - Ivy league, fancy sounding name.
6. Georgetown - Fancy sounding name, famous institution
At this point, lay prestige starts washing out with the "average joe" guy who didn't go to college. IE the guy at the party who got his b.s. (bulshit) culture degree from north-southeastern-low standards college will significantly drop down in the "OMG wowww" response when your parents brag about your law school. So from here on, it basically comes down to what very educated people know about the institution.
7. Chicago - Home of many, many famous thinkers of the 20th century, especially in regards to economics. While many will think it's a shitty local school, the impression you will leave on the educated who know that it is a rigorous, intense university will be enough to bump it up.
8. Berkeley - 2nd best school on the west coast in almost every regard, and people know this. And Cal is generally regarded as the #1 or #2 public in the country. Plus the name sounds really fancy. Next years "MST" rankings, it could be number 7! Watch out Chicago!
9. Penn - Obviously the most "prestigous" undergrad of the bottom prestige tier, Penn get's f'd because it sounds like a state school and is frequently confused with Penn State, which people equate with a football powerhouse state school, not a nerdy or prestigious institution. Even if they know its not Penn State, most people are surprised to realize its an Ivy from my experience. But Ivy league status and knowledge among the business elite is enough to bump it up above the other 5.
10. Duke - Great name. Great undergrad. But kind of regional for undergrad matriculation, and that effects its rep. Nobody is confused that this school is shitty, but nobody is confused it is harvard either...
11. Northwestern - Great undergrad program and national reach for recruitment for undergrad + rather reputable name keep this out of the bottom 3.
12. Virginia - Everyone knows its a great state school but nobody who doesn't know about law school would ever think it's a "Top 10" schools in the nation with a law school, simply because they assume most of the better schools (IVY, Stanford, etc.) are better.
13. Michigan - Same as Virginia, to a lesser extent. I'm betting people think that the law school is tied into the regional market, and since everyone knows the state of Michigan sucks right now, they'll wonder why you had to go here if you didn't have to.
14. NYU - No undergrad prestige at all. Even the characters of gossip girl bolted to columbia this season for greener pastures. Despite NYU being a perennial top 5 law school, nobody outside of law is aware of this. Sucks to suck.
FOR MID ATLANTIC: BUMP UP PENN, DUKE
FOR MID WEST: BUMP UP NORTHWESTERN, CHICAGO
FOR WEST: BUMP UP BERKELEY
FOR SOUTHEAST: BUMP UP DUKE