Next year’s election is 17 months away, but the latest private betting on Wall Street strongly shows that the Street’s big hitters are becoming increasingly convinced that Senator Clinton is headed back to 1600 Pennsylvania for another four-year stay.

The newest bet, the single biggest such Street election wager I’ve heard about — one that’s illegal in America and which I’ve confirmed — is a $350,000 wager that Mrs. Clinton will win the presidency.

Four people are involved in this bet. The largest amount — the entire $350,000 — is being put up by a well-publicized billionaire investor in the metropolitan New York area who is convinced, he told me, that “Hillary can’t miss.” On the other side of the bet are a retired hedge fund manager and a top official of a buyout firm, each of whom is anteing up $125,000, and a Big Board specialist who is in for the remaining $100,000.

If the former first lady doesn’t get the Democratic Party nomination or withdraws from the presidential race for any reason, our billionaire automatically loses. If she dies before the election, the bet is off.

Over the past six months or so, I have done several columns on private Wall Street wagers on the election. This latest bet on Mrs. Clinton raises to about $800,000 the amount of money well-heeled investment pros have wagered on the former first lady to win either the Democratic nomination or the presidency.

While Mrs. Clinton’s most formidable Democratic rival, Senator Obama of Illinois, has his Street boosters among Democrats, as does a former presidential candidate, Vice President Gore, the mounting Street view is the presidency is now Mrs. Clinton’s to lose.

Although the New York senator is frequently described as a polarizing figure, the growing view among political pundits is that she’s running an effective campaign, the scars of her war vote are fading, and doubts within the Democratic Party about her electability are fast diminishing. Yet other key pluses are said to be an imposing war chest and her husband, President Clinton, who remains a darling among activist Democrats.

Even some Republican investment pros are impressed with her campaign. “Hillary is a strong candidate and she’ll be tough to beat,” a Boston investment adviser, Bill Rhodes, tells me. “Keep in mind, too,” he adds, “the economy did very well under her husband’s watch, and people will remember that.”

One of Wall Street’s most respected political trackers seems to sum up the mood: “Hillary represents a government in waiting.”

Based on its latest odds, Britain’s largest bookmaker, William Hill, tends to agree. “In the presidential sweepstakes, she’s now in a league with Tiger Woods and Roger Federer: no. 1,” a spokesman told me.

Mrs. Clinton, quoted at odds of 1 to 1 — you put up a buck to win $1 — is the overwhelming favorite. Six months ago, she was quoted at 3 to 1.

Mr. Obama and Mayor Giuliani are tied for second place at 5 to 1 (you put up $1 to win $5 for a total return of $6). A former Tennessee senator and “Law and Order” star, Fred Thompson, who is expected to announce his entry into the race early this month, is close behind at 6 to 1. Mr. Gore follows at 12 to 1.

Rounding out the top dozen leading presidential candidates as far as the betting odds go are a former Massachusetts governor, Mitt Romney (14 to 1), Senator McCain of Arizona (14 to 1), a former North Carolina senator, John Edwards (16 to 1), Governor Richardson of New Mexico (50 to 1), Senator Dodd of Connecticut (66 to 1), Senator Biden of Delaware (66 to 1), and a former speaker of the House, Newt Gingrich (80 to 1).

Several consultants and analysts who cover the Washington scene for some top brokerages and mutual funds suggest to me that Mr. Obama has peaked, Mr. Edwards is falling, Mr. McCain is “dead in the water” because of his support for the war, and Mr. Giuliani’s appeal is diminishing. As one consultant put it, “Everything is coming up roses for Hillary, and her rivals know it but won’t acknowledge it.”

Although there continues to be a great deal of press speculation about Mayor Bloomberg’s possible entry into the presidential race, the folks who set the political odds at William Hill don’t believe it. In fact, they view him as such a noncandidate that they recently eliminated his name from their betting list. That’s after his inclusion on the list about six months ago at 50 to 1 and a reduction in the odds two months ago to 34 to 1. “The press is hyping him as a last-minute entry, but it looks like he’s a nonentry,” the William Hill spokesman said.

dandordan@aol.com