It’s as certain as death, taxes, and another TV appearance by Donald Trump. Come Thursday evening, delegates at the Republican National Convention at Madison Square Garden will nominate George Bush for another four-year term.

The problem for the Republicans is they’ll be nominating a loser, according to investment adviser James DiGeorgia, publisher of 21st Century Investor, an eight-year-old monthly market newsletter out of Boca Raton, Fla. Not only that, he believes John Kerry could snare the White House in a landslide victory that would whack the stock market.

No, Mr. DiGeorgia is not a Democrat, but a registered Republican and a conservative to boot. Though a Bush supporter, he said: “I’m not going to put my head in the sand or hope for a November miracle. At this point, the election is Kerry’s to lose.”

He is so sure he’s right that he recently fired off a promotional piece to potential new subscribers that declared: “Bush is headed for defeat and stocks will plunge!”

The polls, as we all know, show the election to be a horse race. Mr. DiGeorgia doesn’t believe it. He figures John Kerry will win by six percentage points on the popular vote and by as many as 90 electoral college votes, which some political pundits might well deem a landslide. His outlook on the popular vote: 51% Mr. Kerry, 45% Mr. Bush, and about 3% Ralph Nader

How does he figure that? Because elections are decided in May, not in October, he argues. And at the end of May, he went on, 60% of the voting public believed the country was on the wrong course. Nearly the same number, Mr. DiGeorgia points out, wanted a change, and Mr. Bush’s overall approval ratings had fallen to the mid-40% level. In fact, at the end of June, Mr. Bush’s approval ratings had fallen further to 42%. These views, notes Mr. DiGeorgia, are pretty much crystallized in voters’ minds and are unlikely to change much by November.

Relating his political outlook to the market, he projects sharp up-and-down stock moves. First, he sees a 10%-15% market gain between mid-summer and early autumn as Wall Street pumps money into stocks in an effort to sustain a pre-election rally. “Obviously,” he said, “Wall Streeters don’t want to see a tax increase on incomes over $200,000 a year, nor a lower exclusion on the estate tax, nor higher taxes on stock dividends. There’s a lot at stake.” Mr. DiGeorgia expects the money inflows into stocks to continue strong until September, at which point, he points out, price/earnings ratios will be stretched to the breaking point. Then, he added, “the reality of Bush’s imminent defeat will begin to set in. And in late September or early October, the market will then start to sell off and crash.”

Elaborating on why he thinks Mr. Bush will lose, our investment adviser cites the following:

* Only 10% of the voting public is undecided, and when the majority thinks the country is on the wrong course, this undecided group historically breaks to the challenger. That means 7 out of 10 undecided votes could go to Kerry.

* Though Bush’s economic policies are creating tens of thousands of new jobs every week, the average Joe and Mary believe their jobs are at risk of being shipped overseas, that their benefits are being reduced to increase corporate profits, and that their cost of living is skyrocketing.

* Ohio, Michigan, Pennsylvania, and West Virginia, representing 64 electoral votes, are must-win swing states. And all of them are in recession today, 2.5 years after the last U.S. recession officially ended.

* While job growth has appeared robust in recent months (except for June), real wages are down. Currently, there’s a $280 billion gap between what workers have today and what they had at this point in the previous six recoveries.

* Labor Department and Census Bureau statistics show that over the past three years, new jobs are paying an average 30% less than the ones lost. Also, take-home pay, as a percentage of the economy, is at its lowest level since the government began tracking such data in 1929.

On another key matter in the political race, Mr. DiGeorgia views Iraq as “a huge problem for the president.” He expects chaos and violence will continue in Iraq because he believes Iraqis aren’t ready for self-governance and that the transfer of power won’t go well. He notes at the end of May, only 40% of the voters approved of Mr. Bush’s handling of Iraq. But at the end of June, when control of the country was turned over to the Iraqis, only 32% approved, meaning Mr. Bush’s numbers actually slipped even in the face of some progress.