Spending by industry associations and companies is tilting more toward Republicans this cycle than in 2008. ABC endorsed Romney in February and is contributing 100% of its dollars to GOP candidates in federal races, compared with 99% in 2008.

To receive an ABC contribution, a candidate needs a minimum 70% score on key congressional votes, Singerling says, including votes on labor-related topics such as project labor agreements (PLAs) and Davis-Bacon Act prevailing-wage requirements, both of which directly affect ABC's open-shop membership. He says, "And for one reason or another, [elected] Democrats...whether they're in a right-to-work state or they're in a heavily unionized state, they are in lockstep with organized labor."

The Associated General Contractors is directing 89% of its funds to GOP candidates this cycle, up from 74% in 2008. Jeff Shoaf, AGC senior executive director for government affairs, explains that in 2008 the parties contained more moderates. "There were a lot more people on both sides that you could consider [for contributions] who weren't taking extreme stands on everything," he says, adding that this year, "It's harder to find people in the middle on big issues that we care about."

At Bechtel Group, contributions show a more even split, with 55% of its dollars going to Republicans and 45% to Democrats. In 2008, the ratio was 50-50. About four years ago, says Jay Farrar, a Bechtel principal vice president and manager of the company's Washington, D.C., office, "There was a recognition that we had to take a harder look at who we contributed to—not just based on party affiliation, but based on the policies that they were supporting." He says that as officials looked at those candidates who were "most aligned with Bechtel's business practices," the list of those to support ended up being fairly bipartisan. But he says, "We don't sit down with a magic formula."

Caterpillar Inc. has contributed 82% of its dollars to Republicans this cycle, up from 75% four years ago. Similar to Bechtel, Caterpillar also doesn't have a "litmus test" of key votes to determine its political spending, says Clay Thompson, director of corporate government affairs. The company is a major U.S. exporter, and Thompson says, "We're looking for candidates who understand the nature of a global business and value increasing U.S. competitiveness." That includes candidates who are "champions of global trade," he adds. Recipients this year include House Ways and Means Committee Chairman Dave Camp (R-Mich.) and Senate Finance Committee Chairman Max Baucus (D-Mont.).

The campaign-finance landscape has been shaken by the rise of huge amounts of spending by super PACs—organizations that can spend unlimited amounts but cannot contribute directly to candidates or parties—in the wake of the Supreme Court's 2010 decision in Citizens United v. Federal Election Commission.

The construction industry's 2012 spending levels have received a huge boost from senior executives' major contributions to super PACs. Among those individuals, the pacesetter by far is Perry Homes owner Bob Perry, who has donated more than $21 million this cycle to Republican-leaning super PACs.

One unusual construction super PAC is the Campaign for Primary Accountability, which helps finance challenges to incumbents (">ENR 7/30 p. 14). Co-founded by Leo Linbeck III, executive chairman of Texas-based Linbeck Group LLC, the PAC's donations of more than $1.5 million from Linbeck himself are included in CRP's listing for Aquinas Cos., the parent of Linbeck Group.

Even so, officials from several industry associations and companies say they have decided not to take the super-PAC route. They generally say they prefer to focus on their own internal PACs.

Among construction unions, the Laborers' International Union of North America (LIUNA) is a major player, having given more than $3.3 million to federal candidates so far in this cycle. LIUNA spokesman Richard Greer says that total is about the same as it was late in the 2008 cycle. Most of the funds are going to Democrats, but LIUNA also donates to GOP candidates who share the union's views on such issues as defending Davis-Bacon and PLAs, Greer says.