Re: Mallory Factor’s piece in support of guest-worker programs: This is less a comment than a supplement. Those farmers, ranchers, hoteliers, constructors, restaurateurs, etc. who can’t get visas for the guest workers they want are shifting their contribution patterns, which traditionally leaned Republican.

Below is a chart of business contributions from business categories whose principal professional groups have endorsed comprehensive immigration reform, including a path to legalization for workers illegally present in the United States. The contribution aggregates were compiled from Federal Election Commission sources by the Center for Responsive Politics.

Contributions in 1996 and 2008 are used as bookmarks. Each represents the first presidential cycle following a mid-term shift from single-party control of the popularly elected federal branches to split control. In neither of these cycles were businesses forced to accommodate single-party control.

Partisan Support in Federal Elections 1994, 2004 & 2008 Industries favoring Comprehensive Immigration Reform Republican Share Democratic Share 1996 2004 2008 1996 2004 2008 Industry Business Associations 85% 85% 77% 15% 15% 23% Food & Beverage Industry 72% 72% 60% 28% 28% 40% Restaurants & Bars 71% 72% 62% 29% 28% 38% Lodging & Tourism 58% 56% 52% 42% 44% 48% Agribusiness 74% 71% 62% 26% 29% 38% Vegetables & Fruits 77% 81% 64% 23% 19% 36% Crop Production & Basic Processing 66% 64% 54% 34% 36% 46% Livestock 76% 78% 66% 24% 22% 34% Poultry & Eggs 80% 75% 64% 20% 25% 36% Forestry & Forest Products 81% 81% 69% 19% 19% 31% Construction 67% 72% 64% 33% 28% 36% Home Builders 66% 78% 66% 34% 22% 34% Special Trade Contractors 71% 74% 69% 29% 26% 31% Computers/Internet 53% 45% 33% 47% 55% 67% Computer Software 48% 40% 33% 52% 60% 67% AVERAGE PARTISAN SUPPORT 70% 70% 60% 30% 30% 40%

Within these groups, $20 of each $100 contributed has shifted from Republicans to Democrats. In general, the shift has occurred within the past four years, following the overwhelming repudiation of comprehensive immigration reform by the House Republican Caucus.

To summarize: In both 1996 and 2004, Republicans enjoyed a 40-cent advantage for each dollar contributed to partisan federal elections among these industry groups. By 2008, that advantage had eroded by one-half: to 20-cents for each dollar contributed.

It is not my intention to present this chart as “proof” of the impact of immigation on the eroding alliance between business and conservatives. Stronger proof exists elsewhere: in the direct statements of the industry groups, in the observations of G.O.P. officials, and in election results in districts in which these industries play a key role. But this chart records a fact: Republican financial support has declined abruptly among those industry groups that support comprehensive immigration reform.

— Richard Nadler is president of the Americas Majority Foundation, a public-policy think tank in Overland Park, Kan.