The vast and cash-rich Koch political network is intensifying efforts behind preferred Republican candidates in the few crucial races that could decide Senate control.
For the first time, some political groups under the umbrella of the billionaire conservative donors Charles G. and David H. Koch are embracing direct endorsement of Senate candidates — a marked shift from the more generic, issue-oriented ads and outreach such nonprofit organizations typically employ to steer voters to chosen candidates.
The push will be a major test of strength for the Koch network, an effort that has been building over the past decade, born of the brothers’ disenchantment with the performance of the Republican Party. The groups already have spent tens of millions of dollars on Senate campaigns.