WASHINGTON—The country’s biggest business lobby will launch an initiative Tuesday to deploy influential Republicans to raise funds for tight Senate races, hoping to keep the GOP from losing control of the chamber in November.
The U.S. Chamber of Commerce’s “Save the Senate” effort is being led by both Republicans who back the party’s presumptive presidential nominee, Donald Trump, and those who have balked at doing so, in a shared quest to retain the Senate majority.
The Chamber’s coalition highlights how much easier it is for Republicans to rally around congressional races this year than to join forces in the divisive presidential election.
Republicans are “are all over the board on the presidential race, but there’s a lot of unanimity when it comes to the Senate,” said Sen. Lindsey Graham (R., S.C.), an honorary co-chairman and fundraiser for the Chamber’s push. Mr. Graham, who ended his own presidential campaign in December, hasn’t endorsed Mr. Trump.
The initiative has no specified fundraising goal. “We’re going to raise as much as we can to be competitive between now and election day,” said Scott Reed, the Chamber’s senior political strategist.
Republicans hold 54 of the Senate’s 100 seats. That slim margin could revert to Democrats’ favor in November, when Republicans will defend 24 seats, including a half-dozen in battlefield states, while Democrats defend just 10.
Democrats must win a net of five seats, or four if they win the White House and secure the vice president’s tiebreaking vote, to regain control of the Senate.
Other Republicans spearheading the new initiative include Mitt Romney, the party’s 2012 presidential nominee; former Florida Gov. Jeb Bush and former Hewlett-Packard Co. HPQ 1.00 % chief executive Carly Fiorina, both of whom ran for president this year; Haley Barbour, a former Republican National Committee chairman and Mississippi governor; Bob Dole, a former Kansas senator and 1996 Republican presidential nominee; Mel Martinez, a former RNC chairman and Florida senator; and former Minnesota senator Norm Coleman.
“When you add up all the networks of the people who are co-chairmen, that’s a pretty big group,” Mr. Graham said.
Many prominent Republicans, including House Speaker Paul Ryan (R., Wis.), as well as Messrs. Romney and Bush, haven’t backed Mr. Trump, whose incendiary comments on women, illegal immigrants and foreign policy have troubled many Republicans.
Other GOP politicians, including Messrs. Barbour and Dole, support Mr. Trump, saying he would be a better choice than former Secretary of State Hillary Clinton, the likely Democratic nominee.
Mr. Trump’s late outreach to traditional GOP donors has left some more focused on the competitive Senate contests.
The Chamber began a $ 10 million ad campaign in May in the handful of swing states where Senate GOP incumbents face the tightest re-election races, including Sens. Rob Portman in Ohio, Kelly Ayotte in New Hampshire, Pat Toomey in Pennsylvania, Ron Johnson in Wisconsin and John McCain in Arizona.
The group is also targeting an open seat in Nevada, currently held by retiring Senate Minority Leader Harry Reid, a Democrat.
Funds generated by the new push will go to broadcast and digital advertising in these states, as well as potentially others later in the year, and events at local Chambers of Commerce, said the group’s Mr. Reed.
“This is one of the most significant elections for the Senate and House in recent American history and it’s imperative we retain pro-business majorities,” Mr. Reed said. “The business community will not be watching from the sidelines.”
Democratic operatives said their candidates and political committees are keeping the fundraising pace with their GOP counterparts and pressing donors to do the same as the party seeks to take back control of the Senate.
An advocacy group headed by Tom Steyer, a former hedge-fund manager turned environmental activist, is spending $ 25 million to boost voter turnout. He is also joining with labor unions to support Mrs. Clinton and other Democratic candidates.
Senate Democrats’ campaign arm raised $ 6.1 million in April, outpacing the $ 4.3 million raised by their Senate GOP counterpart. The Democratic group has $ 20.9 million in cash on hand, slightly below the $ 21.6 million held by the Senate Republicans’ group.
Money from the business lobby will only make vulnerable Republicans look beholden to industry groups, said Lauren Passalacqua, a spokeswoman for Senate Democrats’ campaign arm.
“If they’re going to rely on this money from corporate special interests to protect their own futures, that’s not going to go well with the voters they’re trying to persuade now,” she said. “Voters want someone who’s looking out for them.”
While Republican candidates have traditionally favored business-friendly policies, including reducing federal regulations, the populist themes of this year’s presidential race have left business groups with few allies at the top of the tickets. Both Mr. Trump and Mrs. Clinton have opposed a sweeping Pacific trade deal, for example, while Democratic rival Sen. Bernie Sanders’s attacks on Wall Street have helped fuel his continuing popularity.
The Chamber, which doesn’t get involved in presidential elections, spent more than $ 70 million on federal races in the 2014 midterm elections.
Republicans face several hurdles in keeping Senate control, which they regained in 2014 after eight years of Democratic control. Greater turnout in presidential election years usually helps Democrats, since these elections tend to attract more Democratic-leaning younger and minority voters. That dynamic could be amplified this year if Mr. Trump’s nomination motivates more women and Hispanic voters to turn up at the polls.
Compounding the difficulty of defending more than twice as many Senate seats as Democrats, Republicans are fighting in some states where President Barack Obama has won. In Florida, for instance, the departure of GOP Sen. Marco Rubio has sparked competitive primaries on both sides of the aisle.
Outside groups, including One Nation, formed last year by Steven Law, a former chief of staff to Senate Majority Leader Mitch McConnell (R., Ky.), are seeking to boost GOP incumbents by running ads stressing their support for local issues.
“It is important for good senators who are popular at home, as these Republican senators are, to keep the focus of the election on that state, that senator’s own record of accomplishment and the record and positions of the challenger,” said Mr. Barbour.
Write to Kristina Peterson at [email protected]