Several Republican strategists acknowledged that widespread crossover voting was organized and encouraged on Tuesday.

No crossover voting was allowed in Tuesday's primary.

In some ways, it was a polarizing outcome, with few signs of the crossover voting that once framed American elections.

In future primaries, where crossover voting is barred, Mr. Bush may well have an easier time.

The motives for crossover voting are sometimes strategic.

Some consider crossover voting to be a form of electoral fraud.

Diminished party loyalty also has hurt the Republicans, with more crossover voting and independent swing voters.

Polls show that the race is close, and the prospect for crossover voting has made it utterly unpredictable.

Democratic leaders have generally expressed unconcern about the Republican effort to stimulate crossover voting.

But the ads failed to induce much crossover voting.