Senator McCain’s pick of Governor Palin to be the Republican vice presidential nominee is historic. Coupled with his party’s platform he enthusiastically embraced, Mr. McCain has completely changed the game, and put Senator Obama in a difficult situation.

The Obama campaign first attacked Mrs. Palin as inexperienced. Then they released surrogates to wage a vicious and personal smear campaign against Mrs. Palin and her 17-year-old daughter, Bristol, who is pregnant.

Teen pregnancy knows no racial, economic, or religious boundaries. The key is how a family deals with the issue. The Palins are giving their daughter the support and unconditional love she needs. They are helping her work through a difficult time her life. Bristol Palin will keep her baby, marry the father, and the three will live their lives. The Palins are working it out and it’s nobody’s business but theirs.

Mr. Obama should be ashamed of his supporters’ conduct. Realizing his surrogates may have stepped over the line with their misogynistic attacks, Mr. Obama quickly tried to change the subject back to experience.

He will find that that argument will backfire too.

First, people understand that it’s unfair to compare the presidential candidate of one party with the vice presidential candidate of the other. Mr. Obama’s opponent is Mr. McCain, not Mrs. Palin. It is the president who makes life-or-death decisions for the country. It is a disastrous mistake for Mr. Obama to raise the experience issue. Mr. McCain’s experience in national security exceeds Mr. Obama’s by orders of magnitude.

Second, Mrs. Palin has more executive experience than Mr. Obama. A governor does a lot in two years. And speaking as a former mayor of a major American city, her years as mayor of Wasilla, Alaska, are full of executive experience. Is she as experienced as Bill Clinton or Ronald Reagan when they first ran for president? No. But she is more experienced than Mr. Obama.

For that matter, Mrs. Palin has more executive experience than the entire Democratic ticket. Her opponent is Mr. Biden, not Mr. Obama. And in all of Mr. Biden’s years legislating, he has never made an executive decision. Even before he was in public life, he never held a job that required him to make leadership decisions.

Between Messrs. Obama and Biden, they’ve never run a corner store, to say nothing of running troops. They do not want to be compared with the commander-in-chief of the Alaska National Guard, Mrs. Palin.

The nature of Mrs. Palin’s experience is also important. She’s a reformer. She has taken on corruption in her own party, and people are now out of office in Alaska because of her crusade to clean up that state. She even challenged the sitting Republican governor of Alaska, Frank Murkowski, and beat him in the party’s primary to restore integrity to Alaska’s state government.

This focuses part of the presidential campaign on reform, and shows that Mr. McCain would press for reform, no doubt with Mrs. Palin in a leading role. Her efforts in Alaska mirror Mr. McCain’s in Washington D.C.

And at least their work has intersected. When Washington sent Alaska that disgraceful “bridge to nowhere,” Mrs. Palin refused the federal largesse, saying if Alaska wanted an expensive bridge they’d pay for it themselves. Contrast that with Messrs. Obama and Biden not joining Mr. McCain’s call to end all earmarks in federal spending, and you have a comparison that the Republican Party welcomes.

Less heralded, Mr. McCain has embraced a solidly conservative Republican Party platform. As a platform committee vice chairman, I can attest to the document’s conservative foundation. It is the most pro-life platform in national party history. And it is a sterling commitment to the sanctity of every human life.

Mr. McCain’s choice of Mrs. Palin shows his commitment to those bedrock moral principles, as she is living proof of a commitment to life. Many now know that she gave birth to a son whom she knew since the fourth month of pregnancy would be born with Down syndrome. She chose to have the baby. And with words that should move many to tears, she said that when she looks at her baby boy, “I see perfection.” I doubt Mrs. Palin would ever say a question of fundamental belief is above her pay grade.

Mr. McCain said in a Sunday interview that the McCain-Palin campaign can be summed up in three words: reform, prosperity, peace. He could have added strength.

Mr. Obama’s supporters thought if they hit Mrs. Palin hard enough she would wither. What they found was a strong woman who will prove to be bigger than their petty politics.

Mr. Blackwell is a columnist of The New York Sun.