A political star was born this week. Her name is Sarah Palin, and she is the governor of Alaska. Whether she is a mere shooting star or a permanent fixture in the political firmament remains to be seen. But Palin electrified the Republican convention in St. Paul, Minn., with her rousing acceptance speech and held the rest of the nation captive. Her powerful performance transformed an otherwise dull convention, and it's doubtful that American politics will ever be the same.

It's clear that the Alaska governor was not Sen. John McCain's first choice for vice president. That would have been his good friend Sen. Joe Lieberman of Connecticut or former Pennsylvania Gov. Tom Ridge. Alas for them, both are pro-choice and thus unacceptable to the Republican party's Christian conservative base. The base itself has never been entirely happy with McCain, and thus McCain's campaign has been in something of the doldrums compared to the electricity in the campaign of Sen. Barack Obama.

The selection of Palin seems to have had two basic purposes. The first was to energize the base of the party, still unenthusiastic about McCain. The second was to appeal to women, most of all those disaffected Democratic women still unhappy that Hillary Clinton was neither the presidential nor the vice presidential nominee. After this week, there is no doubt that Palin has energized the entire Republican party, especially the base. The Republicans now seem to be four-square behind the McCain-Palin ticket. That makes a big difference. But the second purpose is much more problematic. People vote for the top of the ticket, not the bottom. And at this point in her career, Sarah Palin is no Hillary Clinton, either in experience or in accomplishment. Palin has just climbed out of the minor leagues; Clinton has been in the majors for years.

The risk with Palin is that she is largely unknown outside Alaska and, given the haste with which she was picked, probably largely unvetted. The McCain camp says no, but the evidence to the contrary is too compelling. Palin was clearly a last minute choice. The negative stories that circulated almost immediately about her is evidence that she was a high-risk choice. Even the Republican party initially seemed uneasy with her. Palin may still turn out to be a high-risk and unwise choice, but her speech to the convention — 93 percent white and more than 60 percent male — put most of those initial fears to rest. The speech was extremely well written and, in her delivery, she knocked it out of the park. The woman from rural Alaska with the unfashionable hairstyle (she looks like a TV sitcom mom from an earlier era) is clearly not intimidated by the national stage. This is a woman who can stalk, kill and dress a moose from the Alaskan wilderness. Democrats beware. Moose, too.

Her speech was extraordinary in delivery but much less so in content. In many ways, it was small-minded and mean-spirited, especially her dismissal of community organizers. This was a slap at Obama, but it failed the test of civility. One can see why Palin in her youth was referred to as "Sarah Barracuda." Behind that million-dollar smile and perky hairdo lies one tough cookie. Moreover, in order to make her point, her speech writers distorted Obama's U.S. and Illinois Senate records to the point of falsehood. He has indeed reached across the aisle to work with Senate Republicans on matters of national security and on ethics. Obama did so at a time when one suspects Palin may never have heard of Georgia and the Caucuses, never mind find them on the map.

The same was true of George W. Bush and the Middle East. He learned, of course, but so did the rest of us, and we paid a heavy price for his ignorance. There are lessons here we don't want to repeat. We do know that Palin is smart, fully capable of using her elbows and knees in political infighting. What we don't know is if she is intelligent. There's a difference.

By way of contrast, McCain is no orator, as he himself admits. His acceptance speech made clear that he is not in the same league as Obama or even Palin. But McCain's speech was remarkably free of the rancor and sheer nastiness that marked the convention speeches of former New York Mayor Rudy Giuliani and South Carolina Sen. Lindsey Graham as well as the Republican convention as a whole. McCain raised the tone.

It is clear that McCain is going to run on character, patriotism and personal biography, by which he hopes to trump Obama. Issues will be secondary. He retold some of his experience as a POW, and it was genuinely moving. In fact, it was the best part of his speech. But his POW story, however inspiring, is well known. It moves us personally, but it is doubtful that it moves his candidacy. The country has moved on and faces new problems. Stirring words about duty to country don't address the issues of jobs, health care and foreclosures.

The Democratic and Republican conventions are now over, and the election campaign begins in earnest. We have a new but untested political star. The polls and the trends favor the Democrats, but we have two months to go. And that's a long time in politics.

William M. Stewart, a former U.S. Foreign Service officer and Time magazine correspondent, lives in Santa Fe. He writes weekly on foreign affairs and politics.