Hillary Clinton’s now-famous “3 a.m.” ad asked voters who they would prefer to answer the phone in the White House if it rang at 3 a.m. in the morning because of a world crisis.

By large margins, voters say “John McCain,” according to a Zogby poll conducted March 13-14. But although the point of the Clinton ad was to stoke doubts about Barack Obama’s experience, McCain’s margins over each is pretty much the same — 55 percent to 37 percent over Clinton, and 56 percent to 35 percent over Obama. In each case, about a quarter of voters who call themselves very liberal favor McCain on this question, and about one-third of mainline liberals feel the same way.

When voters of all party’s are asked that question about just Clinton and Obama, Clinton leads just 37 percent to 36 percent with 27 percent unsure. Just among Democrats, Clinton leads Obama 48 percent to 38 percent, with 14 percent unsure.