(c) 2013, Bloomberg News.

(c) 2013, Bloomberg News.

FOLEY, Ala. The U.S. Chamber of Commerce has fired an opening salvo in the battle for control of the Republican Party, endorsing a self-described "pro-business" candidate in a special House race whose opponent is backed by tea party groups and is vowing to "be like Ted Cruz."

Tuesday's endorsement in the Alabama contest is the chamber's first political move since the 16-day partial U.S. government shutdown and debt-ceiling battle, which exposed a rift between the Republican establishment wing and the smaller-government movement. Cruz, a Republican senator from Texas, was the chief proponent of the ill-fated plan to link defunding Obamacare to lifting the debt ceiling and passing a government spending bill.

In reaction to the shutdown, which Standard & Poor's estimated cost the U.S. economy $24 billion, the chamber and other business groups said they will engage in elections including Republican primaries to help candidates aligned with their economic goals.

"Absolutely we want to send a message," Rob Engstrom, the chamber's national political director, said Tuesday after the group endorsed Bradley Byrne, 58, in Alabama's 1st Congressional District race. "We are sending a message here today, and we will send a message in every single one of these races. Some will be in primaries, some will be in general elections."

The winner of Alabama's Nov. 5 primary runoff will compete to fill the seat vacated by Jo Bonner, a Republican who resigned in August to become vice chancellor of the University of Alabama system. The opening provides a rare opportunity this year for each side in the Republican conflict to measure the other and score a first victory.

Byrne or his Republican opponent, Dean Young, 49, will face Democrat Burton LeFlore, 47, a Mobile real estate agent, in a Dec. 17 special election in a district that backed Republican Mitt Romney over President Obama in 2012.

Getting involved in such contests, business leaders and others have said, is important to repairing the Republican brand before the 2014 midterm elections, when the party will seek to hold its majority in the House and win a net six seats to gain control of the Senate.

"In addition to protecting that majority, we're also interested in what is the composition of that majority," said Engstrom, referring to the Republican-controlled House. "We want to find candidates that come from the private sector."

The chamber has spent more than $185,000 for direct-mail and digital media ads supporting Byrne since making the endorsement Tuesday, according to financial disclosure reports filed Wednesday.

Republican prospects, especially in the Senate, dimmed after the shutdown and debt-ceiling fight sparked by Cruz and the tea party wing of the House Republican caucus. The impasse led to a record-low 28 percent favorability rating for the party, according to an Oct. 3-6 Gallup Poll of 1,028 adults with a margin of error of 4 percentage points.

The Alabama contest is also being watched by Republican House incumbents who've run afoul of limited-government groups. Some are donating to Byrne's campaign.

Americans for Prosperity and Club for Growth, two organizations affiliated with tea party groups, are backing candidates to challenge lawmakers they deem too willing to compromise.

"It'll depend on who will be most successful in motivating their base, the business base versus the tea party base," Bill Armistead, the Alabama state party chairman, said of next week's primary. "It's going to be a very competitive race."

The two Republicans emerged from a 9-person primary on Sept. 24 as the top vote-getters with neither receiving more than 50 percent, which forced a runoff.

Soon thereafter, donations began streaming into Byrne's campaign from political committees run by Wal-Mart Stores Inc., AT&T Inc., Exxon Mobil Corp., Comcast Corp., Lowe's Cos., the National Realtors Association and the Alabama Retail Association, among others.

Much of that money was donated in the first two weeks of this month amid the government shutdown that began Oct. 1.

Byrne's campaign contributions of $689,215 give him an 8- to-1 fundraising advantage over Young, a property developer who has raised $85,547. Young has loaned his campaign $174,500, according to Oct. 24 financial-disclosure reports.

Political action committees belonging to House Majority Leader Eric Cantor, R-Va., and Republican Reps. Renee Ellmers of North Carolina, Ken Calvert of California, Steven Palazzo of Mississippi, Martha Roby of Alabama are among those that have given to Byrne.

The $10,000 in donations from Cantor's leadership PAC, Every Republican is Crucial/ERIC, are recorded as being delivered on Oct. 16 the day Congress voted to reopen the government and lift the nation's $16.7 trillion debt ceiling.

Byrne is pitching himself to voters as a pragmatist who can work effectively in Washington. He has touted his business credentials as a lawyer and a board member for two local chamber of commerce groups.

The U.S. chamber endorsement took place at a Vulcan plant, a sign manufacturer based in Foley, Ala. A dozen employees stood behind Byrne, a former state senator who ran unsuccessfully for governor in 2010, at the event.

"They're looking for someone who is going to be part of the solution, not part of the problem," he said in an interview after the endorsement. "My opponent is someone who would be part of the problem."

In a reference to Young and Byrne, Engstrom said, "Anybody can stand on the street corner and shout, but who's the candidate that can get something done?"

Young is highlighting his opposition to same-sex marriage and abortion rights while campaigning in the coastal Alabama district, which includes Mobile. During the early stages of the Republican primary, Young asked candidates to sign a pledge affirming a position against gay weddings.

Young's campaign didn't respond to emails and calls.

"You guys need to send me up there. I will be like Ted Cruz," he said Oct. 24 on "The Uncle Henry Show," a program aired in Mobile by Fox News Radio. "I will not compromise on principle. We don't need to raise the debt ceiling. We don't need Obamacare."

He also urged listeners, if he wins, to get "you a big old thing of popcorn and a Big Super Gulp and lean back and turn on C-SPAN. Because I promise you, I will stand on the floor of the House and stand for the principles that we believe in that made this nation great."

The candidates sparred over the importance of the U.S. chamber endorsement during a candidate forum Tuesday sponsored by the Eastern Shores Chamber of Commerce in Daphne. Young said he wouldn't accept it, citing the national chamber's support for a revision of immigration laws.

"The chamber of commerce, last week, said that they wanted to provide amnesty to 11 million illegal immigrants in this country," he said. "I would not accept that endorsement and I definitely wouldn't be out bragging about it."

The chamber's Engstrom said Young had initially sought its endorsement, returning a candidate questionnaire within 24 hours.

Byrne said he would go to Washington to reduce government and repeal the U.S. Patient Protection and Affordable Care Act. While Young also made those points, Byrne said he would be more effective as a deal-maker

"We've got far too many people who want to be problem makers, not problem solvers," he said.