Primary surprises

Sen. Lisa Murkowski of Alaska is the latest incumbent to fall in the uncertain political climate.

The senator lost a close race to political newcomer Joe Miller in the state's Republican primary for the U.S. Senate seat.

Mr. Miller received the support of former Gov. and Republican vice presidential candidate Sarah Palin.

Sen. Murkowski was targeted for defeat by the Sacramento Tea Party Express that pumped $600,000 into Mr. Miller's campaign, more than half of that amount in the last week before the vote, according to McClatchy Newspapers. The group recruited Ms. Palin to speak on Mr. Miller's behalf.

The Tea Party Express, formed by GOP consultant Sal Russo, has targeted and helped to defeat other Republican incumbents or high-profile candidates this year, causing the nomination of Sharron Angle in Nevada and Mike Lee in Utah, who beat Sen. Bob Bennett.

Its next target is nine-term Republican Congressman and former Delaware Gov. Mike Castle, who is being challenged by conservative Christine O'Donnell. The group has spent more than $500,000 in Ms. Angle's quest to unseat Senate Majority Leader Harry Reid in Nevada.

Populist ferment fueled by big money cleverly spent can mean trouble for incumbents, if they are vulnerable.