This technique is 100 percent legal and especially effective in rough primary battles.

How heated has the primary battle for Manhattan district attorney become?

It's certainly not because the primary battle will be easy.

It will be his first primary battle since 1964.

And it is worse for Republicans, who have never had a serious primary battle before, because most of the city's residents are Democrats.

In addition, the tough primary battle left him short of money.

Governors' support has historically proved important in primary battles and general elections.

A decade ago, party leaders would have been far more likely to meet and agree on a candidate to prevent any primary battle.

The numbers are not large, but the year has produced some high-profile retirements and primary battles.

A nasty primary battle among Democrats could work to the advantage of Republicans.