More often than not, the role of a vice president is a minor one, unless some tragedy occurs. But a presidential nominee's choice of a running mate is vitally important. It is his first executive decision and offers an important insight into how that nominee would lead the nation.

    If John McCain wants voters to conclude, as he argues, that he has more independence and experience and better judgment than Barack Obama, he made a bad start by choosing Gov. Sarah Palin of Alaska.

    Mr. McCain's supporters are valiantly trying to argue that the selection was a bold stroke that shows their candidate is a risk-taking maverick who - we can believe - will change Washington. (Mr. Obama's call for change - now "the change we need" - has become all the rage in St. Paul.)

    To us, it says the opposite. Mr. McCain's snap choice of Ms. Palin reflects his impulsive streak: a wild play that he made after conservative activists warned him that he would face an all-out revolt in the party if he chose who he really wanted - Senator Joseph Lieberman of Connecticut.

    Why Mr. McCain would want to pander to right-wing activists - who helped George W. Bush kill off his candidacy in the 2000 primaries in a particularly ugly way - is baffling. Frankly, they have no place to go. Mr. McCain would have a lot more success demonstrating his independence, and his courage, if he stood up to them the way he did in 2000.

    As far as we can tell, Mr. McCain and his aides did almost no due diligence before choosing Ms. Palin, raising serious questions about his management skills. The fact that Ms. Palin's 17-year-old daughter is pregnant is irrelevant to her candidacy. There are, however, very serious questions about her political past and her ideology.

    If Mr. McCain wanted to break with his party's past and choose the Republicans' first female vice presidential candidate, there are a number of politicians out there with far greater experience and stature than Ms. Palin, who has been in Alaska's Statehouse for less than two years.

    Before she was elected governor, she was mayor of a tiny Anchorage suburb, where her greatest accomplishment was raising the sales tax to build a hockey rink. According to Time magazine, she also sought to have books banned from the local library and threatened to fire the librarian.

    For Mr. McCain to go on claiming that Mr. Obama has too little experience to be president after almost four years in the United States Senate is laughable now that he has announced that someone with no national or foreign policy experience is qualified to replace him, if necessary.

    Senator Lindsey Graham, the South Carolina Republican who has been one of Mr. McCain's most loyal friends, said Tuesday that he was certain that Ms. Palin would take the right positions on issues like Iraq, Russia's invasion of Georgia and Iran's nuclear weapons ambitions. That seemed based largely on his repeated assertion that Ms. Palin would be tended by Mr. McCain's foreign policy advisers. That was not much of an endorsement.

    Some of the things Ms. Palin has had to say in the recent past about foreign policy are especially worrisome. In a speech last June to her former church in Wasilla, Ms. Palin said the war in Iraq was "a task that is from God." Mr. Bush made similar claims as he rejected all sound mortal advice on how to conduct the war.

    Mr. McCain, Mr. Graham and others also claim that Ms. Palin is a fearless reformer who is committed to fighting waste, fraud and earmarks. Ms. Palin did show courage taking on some of the Alaska Republican Party's most sleazy politicians. But she also was an eager recipient of earmarked money as a mayor and governor.

    Mayor Palin gathered up $27 million in subsidies from Washington, $15 million of it for a railroad from her town to the ski resort hometown of Senator Ted Stevens, now under indictment for failing to report gifts.

    The Republicans are presenting Ms. Palin as a crusader against Mr. Stevens's infamous "Bridge to Nowhere." The record says otherwise; she initially supported Mr. Stevens's boondoggle, diverting the money to other projects when the bridge became a political disaster. In her speech to the Wasilla Assembly of God in June, Ms. Palin said it was "God's will" that the federal government contribute to a $30 billion gas pipeline she wants built in Alaska.

    Mr. McCain will make his acceptance speech on Thursday, and Ms. Palin will speak on Wednesday. Those two appearances will go a long way to forming voters' views of this Republican ticket.

    As Senator Graham noted, Mr. McCain has to reach out beyond the party's loyal base. "We're going to have to win this thing," he said. "This is not our race to lose."

    Mr. McCain's hurdles are substantial. To start, he has to overcome Mr. Bush's record of failures. (The president addressed the convention Tuesday night and now, McCain strategists fervently hope, will retire quietly to the Rose Garden.) That record includes the disastrous war in Iraq, a ballooning deficit, the mortgage crisis - and the list goes on.

    To address those many problems, this country needs a leader with sound judgment and strong leadership skills. Choosing Ms. Palin raises serious questions about Mr. McCain's qualifications.