Dear Millennial:

The passion that millions of young voters have for Senator Obama is very real and unlikely to waver in the least bit absent excellent and detailed appeals to their reason. There are tremendously appealing reasons to support Mr. Obama, especially for those of your generation, born in the 1980s. You think the country is broken, its politics bitter and boring, elected officials stupid, and President Bush and Vice President Cheney at best incompetent and at worst evil. The only way to change a young voter’s mind about supporting Mr. Obama will be to sincerely and persuasively explain to them why the charismatic senator from Illinois would be a disaster as the president and how that will gravely impact their future. You parents of millenials are also thinking about a decision not to vote for Mr. Obama. You have to make an adult case to your adult children based on the facts.

Here is my case:

All day, every day, a president decides.

The pressure of the job is enormous, constant, and unrelenting in its intensity. The toll it takes on office holders often has been seen in their faces or the graying of their hair. Unless you have been president or very close to one, you really have no idea of the awesome demands of the job, and even the best presidential historians only glimpse it and imperfectly convey it to us.

If I am correct, and Mr. Obama is woefully unprepared to begin making these thousands of decisions each year in office — dozens every day from day one — and making them correctly, the consequences will begin to roll out immediately.

A president can screw up the economy and thus your life in profound and lasting ways.

He can also get a lot of Americans killed.

Inexperience in the business of making decisions makes it far more likely that he will do one or both. And Mr. Obama is almost wholly inexperienced in that business …

Why I am I so confident that Mr. Obama is going to make all the wrong choices on the economy and entitlement reform? In addition to what he has said he would do, as in his firm pledge to raise taxes and not extend the Bush tax cuts, and what he has done in refusing to work responsibly toward any sort of entitlement reform solution for Social Security and Medicare, we also know what he doesn’t know — the impact of government on business.

Put simply, Mr. Obama has never run a business or even been employed by one other than as a junior lawyer in a law firm and for a few months as an “analyst” of some sort out of college. After that stint and before he went to law school he spent three years as a “community organizer,” which is a sort of political activist who believes in mobilizing small communities of people to bring pressure to bear on public officials in order to obtain more or better city services.

Whether or not you believe this to be noble work, it certainly doesn’t create jobs or products. In fact, reading Mr. Obama’s account of those years in his first book, “Dreams From My Father,” leads a reader to conclude that Mr. Obama has almost no clue as to how the economy works or how jobs are created, a gap certain not to have been reversed by a few years practicing law or in the Illinois state senate and Washington, D.C. Every problem he has seen or worked through — and he has considerable experience trying to help people at the very bottom of the economic pyramid — has been in some way connected to prying something out of the government — a new grant, a new program, a different policy, a new statute.

Mr. Obama shouldn’t be expected to understand profits and losses when he has never been responsible for managing a bottom-line business. His law firm experience won’t help much since he never rose to its management, and even that sort of management — of lawyers billing by the hour — is far removed from the manufacturing and sale of products to consumers — the heart of our economy.

The consequence of a life spent filing voting rights or housing discrimination law suits or in the employ of the government is, unfortunately, a huge blind spot concerning how jobs and wealth are actually created, a suspicion toward those who do create them, and an indifference to the value of a few dollars more or less in the bank account of a business owner. If you have never had to pay spiraling worker’s compensation insurance bills or been wrongfully sued by a shakedown artist masquerading as a “plaintiffs’ lawyer,” you simply have no idea how such things can destroy the business you are attempting to build.

Last year a young man approached me with an idea for starting a music store that offered music lessons. He didn’t have any capital and wondered if I would like to invest in return for a share of the ownership. He worked through his business plan, valued his business, and I invested with him.

Almost immediately the plan hit bumps in the road, especially long delays in getting improvements to his leased space, which had to be approved by the city bureaucracy. As he was paying rent for the space, money drained from advertising or office supplies, or a Web site that could generate business leads.

This is the sort of experience that Mr. Obama knows nothing about — the sweating of a new business launch, the incredible frustration of being stopped by a government that doesn’t work fast or past 5 p.m. or ever on weekends, even though you do.

Mr. Obama’s inexperience threatens your ability to make your own dreams come true because he simply will not appreciate the consequences of the choices pushed on him by, say, environmental activists worried about urban sprawl or endangered species. This experience gap will lead him to the sorts of errors that plagued Jimmy Carter’s tenure as president from 1977 to early 1981, which produced his dismal economic record.

That is going to cost you and your future family money, and all that ownership and independence mean in life.

Now to the war in Iraq, and the struggle against jihad around the world.

Unless you are in the military, in all likelihood you haven’t spent a lot of time thinking about the nature of our enemy. Besides, a lot of what is said and written about the war is just plain silly, the inevitable product of lazy habits of analysis combined with faulty premises built on bad facts.

I am certain — convinced beyond any doubt — that any American who is willing to read a dozen books with an open mind will reach the conclusion that we are in extraordinary peril from a growing population of radical jihadists getting closer to obtaining weapons of mass destruction which they will not hesitate to use.

I am also certain that armed with the facts available in these books, any fair observer will recoil from the naïveté that Mr. Obama has expressed in this campaign, such as when he announced his willingness to meet without preconditions with Iran’s fanatical president, Mahmoud Ahmadinejad, North Korea’s brutal dictator, Kim Jung Il, or the new fascist to our south, Venezuela’s Hugo Chavez; or when he declared a willingness to invade our ally Pakistan, which has scores of nuclear weapons and a long-running battle with its own domestic terrorists; or when he scoffed at the idea that Al Qaeda was already in Iraq.

Over and over again, Mr. Obama shows a world view that seems certain that the world’s problems exist because of America’s actions, and that we could meaningfully advance our safety by diplomacy with the world’s most ruthless killers.

Yes, he is a gifted speaker. But his words conceal policies which will produce an America you will not like, an economy that will not work, and a defeat in a war, the consequences of which are too terrible not to ponder long and hard.

Mr. Hewitt is the host of “the Hugh Hewitt Show.” This material is excerpted from his pamphlet, “Letter to a Young Obama Supporter,” out this month from the New Pamphleteer, at pamphletguys.com.