The success of Mrs. Clinton and Mr. McCain followed their third- and fourth-place finishes in the Iowa caucuses last week. Mrs. Clinton’s victory came after her advisers had lowered expectations with talk of missteps in strategy and concern about Mr. Obama’s momentum after his first-place finish in Iowa. Her team is now planning to add advisers and undertake a huge fund-raising drive to prepare for a tough and expensive fight with Mr. Obama in the Democratic nominating contests over the next four weeks.

Mr. McCain had pursued a meticulous and dogged turnaround effort: his second bid for ...