Thomas Dewey, Franklin Roosevelt, Al Smith, Theodore Roosevelt, and John Davis. That is a list of major party presidential nominees from New York during the 20th-century prior to 1950. Who is on the list of 20th-century major party presidential nominees from New York after 1950? Nobody.

In the same period during which New York presidential candidates have failed to become their parties’ nominees, New England candidates have flourished. John Kennedy, Michael Dukakis, John Kerry, all of Massachusetts, were nominated to top the Democratic ticket. Paul Tsongas, a former U.S. senator from Lowell, Mass. — just across the border from New Hampshire — won the primary and gave President Clinton a run for his money in 1992.

What makes all this more than trivia is that the 2008 presidential contest is likely to have two major candidates from Massachusetts — Senator Kerry and Mitt Romney, the state’s governor — and two from New York — Senator Clinton and Rudolph Giuliani. (A September CNN/Opinion Research Corp. poll had both Senator Clinton and Mr. Giuliani as the favorites for their respective parties’ presidential nominations.)

There have, of course, been big names from New York whose names have been raised in presidential contests. Jack Kemp of Buffalo was running mate to Senator Dole of Kansas in 1996. Geraldine Ferraro, a congresswoman from New York, served as Vice President Mondale’s running mate in 1984. Governor Cuomo dashed the hopes of Democratic activists, salivating since his 1984 convention speech over the prospect of a presidential run by him, when he kept a New Hampshire-bound plane waiting on the tarmac in 1992. Nelson Rockefeller’s failure to receive the GOP’s nomination could be interpreted as having more to do with his own personal failings and liberal political leanings. And as a New York senator, Robert F. Kennedy appeared to be headed toward the Democratic nomination when he was assassinated in 1968. But Mr. Kennedy was essentially a cultural New Englander, and no New Yorker has headed up a presidential ticket since Dewey in 1948.

The Democratic National Committee’s addition of a caucus in Nevada between the Iowa caucus and the New Hampshire primary could change this half-century fact of presidential politics. “Just getting New Hampshire out of the mix” is likely to help presidential candidates from New York, says Garrison Nelson, a political science professor at the University of Vermont, who has published a paper on the advantage of New Hampshire during the primary season. “The New Hampshire primary has awarded the Northeast candidacy to New England instead of New York for more than 50 years.”

The New Hampshire advantage is about more than mere geographic proximity. Southern New Hampshire is considered part of Greater Boston’s television market. While New Hampshire boasts several homegrown television stations — including the influential WMUR of Manchester — Boston stations dominate the voter-rich southern tier. That translates to almost unlimited penetration into New Hampshire for Mr. Romney, who oversaw the aftermath of the closing of the Central Artery this summer. As the governor based in Boston, Mr. Romney commands more TV coverage than Senator Kerry who must divide time between Boston and Washington.

Candidates from neighboring states are also helped by the Federal Election Commission’s system of state spending caps for primaries. Presidential candidates who accept federal matching dollars are limited to spending certain amounts in each state. A Massachusetts or Vermont-based presidential candidate such as Howard Dean can get around the state cap in New Hampshire by spending in his home state.

Right now, prospective Democratic candidates appear to be hedging their bets.Yesterday both Senator Bayh of Indiana and Governor Richardson of New Mexico were in New Hampshire. John Edwards and Mark Warner, the former governor of Virginia, meanwhile, have both made trips to Nevada during the last month. A visit from President Clinton to Las Vegas is not out of the question.

On the Republican side, Mr. Giuliani is slated to speak in Manchester, N.H. on October 12 for a group whose objectives include preserving the Granite State’s early primary status, VictoryNH.

Democratic strategist and Fox News Channel analyst Mary Anne Marsh says New Hampshire will maintain its importance even with the addition of the Nevada caucus. “The reality is for the rest of the country, the presidential campaign doesn’t start for them until the New Hampshire primary,” she said. “They have spent the last 50 years trusting New Hampshire voters to take on [the candidates’] character.”

To win New Hampshire, Mr. Giuliani will have to out-do, among others, Senator McCain, who already won New Hampshire handily in 2000, and Mr. Romney, who has spent a succession of weekends in New Hampshire for years — not as a presidential candidate but as a vacationer who owns a home on Lake Winnipesaukee. Mr. Giuliani could be helped by the fact that Manchester, Nashua, and the communities in between more resemble exurbs with voters who have emigrated to the area from big cities.

And, even with the addition of the Nevada caucus, it’s too early to think that Senator Clinton, if she runs, won’t make her presence felt in the state that made her husband the “Comeback Kid” in 1992. Nevertheless, the primacy of New Hampshire could be the missing factor that determines the success of Senator Clinton, Mr. Giuliani, Senator Kerry, and Governor Romney.

Mr. Gitell is a contributing editor of The New York Sun.