The letter, first obtained by liberal magazine In These Times, said: “If we elect candidates who want to spend hundreds of billions in borrowed money on costly new subsidies for a few favored cronies, put unprecedented regulatory burdens on businesses, prevent or delay important new construction projects, and excessively hinder free trade, then many of our more than 50,000 U.S. employees and contractors may suffer the consequences, including higher gasoline prices, runaway inflation, and other ills.”

It also states: "First, and most important, we believe any decision about which candidates to support is — as always — yours and yours alone."

The Koch brothers, who made their billions in the oil-and-gas industry, have spent considerable sums supporting Republican candidates through direct contributions from Koch Industries and through conservative super-PACs such as Americans for Prosperity.

ADVERTISEMENT

A letter like the one Koch Industries sent is comparable to those sent by unions and trade organizations, Tappan said, and therefore is “not unusual.”

Tappan noted the firm also included information employees “often request” about voter registration deadlines, early voting options and candidates supported by Koch companies and KOCHPAC, the firm’s employee political action committee.

“Indeed, unions and newspapers go further than this and actually endorse candidates to their readers and members,” he said.