Since announcing their presidential bids, the five Democrats who will be on the stage during the first debate in Las Vegas on Tuesday have made 391 campaign stops around the country, according to data compiled by the National Journal.

If you lay all of that travel onto a map, with each candidate originating in his or her campaign's home base, the focal points of attention are obvious. Of the 391 stops, 131 were in Iowa and 100 were in New Hampshire, as you might expect.

No one has hit more locations than Hillary Clinton, but her travel has been more diverse.

Hillary Clinton
Stops in Iowa: 32
Stops in New Hampshire: 22

Clinton has visited 31 states, according to the National Journal data — 10 more than the runner-up. She's visited Iowa and New Hampshire frequently, but also Florida, California and South Carolina. (Why California? $$$.)

At the other end of the spectrum is Jim Webb.

Jim Webb
Stops in Iowa: 4
Stops in New Hampshire: 3

Webb's shoestring campaign (if it is a campaign) has only taken him to a handful of states.

Martin O'Malley
Stops in Iowa: 47
Stops in New Hampshire: 21

The always-energetic Martin O'Malley, on the other hand, has made stops in Iowa more than any other candidate, according to the data. He's been to 17 states from his home base in Baltimore. And yet he's only one point ahead of Webb in Iowa — and trailing Webb overall.

Lincoln Chafee
Stops in Iowa: 8
Stops in New Hampshire: 23

Chafee (who trails both Webb and O'Malley) has put a special emphasis on New Hampshire, which is driving distance from his Rhode Island home. Of the five candidates who will be on the stage on Tuesday, Chafee is polling fifth in New Hampshire. If you add in Joe Biden, Chafee is polling sixth.

Which brings us to Mr. Sanders.

Bernie Sanders
Stops in Iowa: 40
Stops in New Hampshire: 31

Sanders has been to 21 states since he announced his candidacy, including a number of visits to South Carolina. Again, there's not a strong correlation between visits and polling: He's been to New Hampshire a lot and leads there, but has visited South Carolina more than any other candidate and trails Clinton badly.

For the non-Clinton and non-Sanders candidates in Tuesday's debate, that reveals the real benefit of the event. Webb will get nearly as much time in front of a national audience tonight as Clinton. Maybe he hasn't visited a lot of states, but thanks to the debate, he'll be in every home that she is.