HATE IS THIN GRUEL:

The primary has been especially bitter for the nomination in state's western district, which includes Concord and is now represented by Ms. Kuster. The front runners are former state Sen. Gary Lambert and state Rep. Marilinda Garcia. Also running is Jim Lawrence, an African-American former state legislator.

Mr. Lambert has raised more money than Ms. Garcia, but she has drawn support from the conservative Club for Growth and other groups from outside the state. She also has won endorsements from national figures such as Sen. Ted Cruz (R., Texas), who is set to appear with her at a rally Sunday.

Mr. Lambert has attacked her position on immigration, with ads accusing her of supporting "amnesty" for people in the U.S. illegally, linking her in his ads with President Barack Obama. She denies that her support for a path to citizenship amounts to amnesty, and her campaign manager calls the attacks a "smear campaign."

The hostility has been intense. After a televised debate this past week, Ms. Garcia refused to shake Mr. Lambert's hand. He responded to criticism of his campaign after the debate, saying, "She may consider it negative. I consider it showing folks where she stands on the issues that are important to people."

In the state's eastern district, Ms. Shea-Porter has personified the political waves that have washed through the nation and the state. She was elected in 2006 in the Democratic wave, defeated in the 2010 GOP landslide and returned to Congress on Mr. Obama's coattails in 2012.

She may face a rematch with the Republican she defeated in 2012 and who beat her in 2010--Frank Guinta, a former mayor of Manchester, the state's largest city, as well as a former congressman. He is considered the favorite in the primary running against Dan Innis, a former business school dean and an openly gay, small-business owner.

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