The national Republican Party is convinced that its inability to win back the Senate in 2010 or 2012 - and possible the presidency in 2012 - was due to extremist candidates winning primary elections, but then losing the general elections. Extremism works when a small group of like minded voters dominate the election, as happens in primary elections, but not when moderates show up, as happens in general elections.
The party is trying to defeat candidates it judges to be extreme at the primary level by throwing money behind moderates who prioritize fiscal and economic issues over social and moral ones.
The danger for the party is that if they alienate the Tea Party, they could lose their support. They wont be voting for Democrats, but they might just sit the election out. Even if they do decide to vote, they may not supply the energy necessary for victory.
It'll be a tough needle to thread.
Here's detail in the NYT:
The Republican Party establishment, chastened by the realization that a string of unpredictable and unseasoned candidates cost them seats in Congress two elections in a row, is trying to head off potential political hazards wherever it can this year.
In House and Senate races across the country, many of the traditional and influential centers of power within the party are taking sides in primaries, overwhelming challengers on the right with television ads and, in some cases, retaliating against those who are helping the insurgents. In Mr. Black’s case, one by one, powerful Republicans started backing his rival, Barbara J. Comstock, a member of the State House of Delegates. First Mitt Romney endorsed her. Then came Citizens United and the president of Americans for Prosperity, the group financed by the wealthy Koch brothers.
A few day after he announced his candidacy, Mr. Black dropped out. “It was pretty evident that she had all the machinery,” he said in an interview.
One of the biggest challenges for Republican leaders in the 2014 midterm elections will be how to hang on to the Tea Party support that has been so instrumental to the party’s growth, while winning back voters alienated by hard-right candidates. These conflicting goals were evident last week as Speaker John A. Boehner of Ohio shelved plans to tackle immigration reform in the House, bowing to pressure from conservatives.
“We’re not picking a fight with the basis for the Tea Party,” said Scott Reed, the senior political strategist for the U.S. Chamber of Commerce, who noted that most Republicans were sympathetic to the free-market, small-government philosophy that inspired the movement. “But some have hijacked the Tea Party model and taken it to an extreme level.”