The National Association of Manufacturers and other business groups have spent vast amounts of time working to convince their membership that they should pressure their employees to vote a certain way in close Republican primaries. It has been reported that the NAM spent a week with upwards of 70 businesses in Kentucky working with employers on ways to get their employees to vote for Senator Mitch McConnell. In Idaho in January, the Business-Industry Political Action Committee worked in the exact same way for Representative Mike Simpson. The theme running is businesses backing more traditional Republican candidates, as opposed to Tea Party candidates, and vocally encouraging employees to do the same. Although businesses are not allowed to threaten any adverse action to employees based on their vote, they may provide as much ?information? as they desire.
See "The new campaign contribution: I?ll get my employees to vote for you", Philip Bump, The Washington Post, May 20, 2014