MOST OF the headlines from Afghanistan ahead of its presidential election Saturday have reported Taliban terrorist attacks, so it’s worth underlining a few bits of less spectacular but probably more important news. Long lines have stretched from election centers as Afghans have registered to vote. Tens of thousands have gathered at the campaign rallies of the leading candidates. Lively debates have been broadcast on television, and women are playing more prominent roles than ever.

In short, notwithstanding the Taliban offensive, there’s reason for hope that Afghanistan will have the election it needs: one that attracts widespread participation and produces an accepted winner to whom incumbent Hamid Karzai can peacefully hand over power. Afghan and international observers say voting in this election is likely to take place in areas that were virtually excluded from the 2009 election, such as the region around Kandahar, and that turnout will probably be considerably higher.

The field of candidates, too, is promising. Of the 11 presidential contenders, the three seeming front-runners are moderate, experienced in government and pro-Western. All say they would quickly sign an agreement with the United States allowing U.S. trainers and counterterrorism forces to remain in the country after this year, the key to maintaining domestic and international confidence in the state constructed over the past dozen years. Mr. Karzai’s refusal to sign the deal and his poisoned relations with the Obama administration mean that the eventual winner of the election — which may require a runoff — will offer a welcome opportunity for a fresh start in U.S.-Afghan relations.

There are, of course, many uncertainties. Some worry that Mr. Karzai and his cronies may try to steal the election for his former foreign minister, Zalmay Rassoul , who appears to be his favorite. Whatever the outcome, there probably will be claims of fraud that a reduced contingent of international observers and weakened electoral complaints commission could have difficulty judging. The new president will have to negotiate the future role of Mr. Karzai, who is building a residence on the presidential palace grounds and will seek to maintain his influence. The Taliban and its backers in Pakistan will surely challenge the new president — especially if it is Abdullah Abdullah, who lost to Mr. Karzai in 2009 and is perceived to represent the non-Pashtun population .

Completion of the vote ought to stimulate swift movement by the Obama administration, which has appeared virtually inert on Afghanistan in recent months. Faced with Mr. Karzai’s recalcitrance, President Obama has declined to commit to a U.S. military mission after this year, much less its dimensions, and the White House has continued to hint at a “zero option.” That has greatly increased uncertainty among Afghans, some of whom are hedging against a state collapse or Taliban resurgence. Mr. Obama should welcome any election that produces a winner accepted by the majority of Afghans, and he should make clear that the United States will support a new government by providing the Afghan army with the training and other assistance it will need.