It’s no secret that a handful of House members are mulling bids for the Senate next year, with several of them all but running their 2018 races already.

Most are in no rush to officially announce their Senate campaigns. Sixteen months is a long time to face the barrage of attacks that comes with running statewide. And in an uncertain political environment, candidates may be taking longer to test the waters. 

But there’s also a much more strategic reason to hold off, and it has to do with the uncomfortable side of politics that candidates don’t talk about on the stump.

Fundraising is the fuel for any campaign. And very lucrative sources of that campaign cash are corporate PACs.

A well-known ‘secret’

Here’s the well-known, but little-talked-about, secret: As long as these lawmakers are House members, and not Senate candidates, they often have access to more of that corporate PAC money.

Members of Congress who sit on influential committees, most often the so-called A committees — rack up contributions from corporate PACs that want to ensure their legislative interests are well-represented. But once incumbents announce they’re leaving the House to pursue a Senate bid, especially if that involves challenging an incumbent senator or another House member in a primary, those PAC contributions often dry up.

“Once you make a determination that you’re leaving, there’s really no obligation for anyone in the PAC community to help you,” one GOP strategist said. 

Even if it’s well-known that those members are planning on running for Senate, until they make it official, PACs have what the GOP strategist called “plausible deniability.” 

“Everyone gets the joke if your name has been floated,” another GOP operative said. 

Corporate PACs shell out money from their employees, and they often have their own boards that dictate how the money can be spent. These PACs regularly donate to members of both parties to protect their interests on Capitol Hill, and they are generally reluctant to donate to anyone who might challenge an incumbent so as not to alienate influential members. 

Likewise, if two House members are running against each other in a primary, PACs aren’t going to want to pick sides.

Nowhere could a member-on-member primary be a more likely reality than in Indiana, where GOP Reps. Luke Messer and Todd Rokita have been sparring out in the open for months. But neither has officially announced his campaign.

Messer ended the first quarter with $1.6 million, and Rokita, who got a slightly later start fundraising for his Senate campaign, wasn’t far behind with $1.5 million. Messer, a member of leadership, serves on the Financial Services Committee. Rokita, vice chairman of the Budget Committee, doesn’t enjoy as plum of a committee spot when it comes to PAC fundraising, but his campaign still wants to make sure he posts an impressive quarter — with a strong showing from Hoosier donors — before announcing.

Indiana Sen. Todd Young is credited with playing this game well when he launched his Senate bid last cycle. Young “proved an important lesson,” one party operative said, by leveraging his spot on the House Ways and Means Committee before making it official that he had other ambitions. 

“We took our sweet time,” said a source close to his campaign. Young announced his bid in the middle of July 2015, right after filing his FEC report for the second quarter, in which he raised a million dollars.  

“We were very successful in the PAC community that quarter,” the campaign source said, adding that the campaign wanted to raise individual money too.

“All we did that quarter is focus on raising money,” the source said.

At the time, Young’s fellow Hoosier Rep. Marlin Stutzman had already announced his Senate campaign several months earlier. The two ran against each other in the primary.

“We wanted to set a marker — people look at these things,” the Young source said.

The optics of a strong quarter can set the tone of a campaign and sometimes alter the field, discouraging other challengers from entering. That’s why the quarter before making an announcement is so important for fundraising.

‘Running without running’

It’s “the stealth quarter,” the GOP operative said. “You’re known to be running without running.”

And House members — because they already hold federal office — can transfer their House committee coffers to a Senate campaign account. That’s an advantage Missouri Rep. Ann Wagner could have over Missouri Attorney General Josh Hawley, who’s been courted as an alternative GOP challenger to Democratic Sen. Claire McCaskill.

It’s old news that Wagner wants to challenge McCaskill. But she hasn’t taken the plunge yet.

A member of the Financial Services Committee, and finance chairwoman for the National Republican Congressional Committee until earlier this year, the Missouri congresswoman has access to big donors.

Wagner set a personal fundraising record during the first quarter of this year, raising $800,000. She ended with $2.8 million in the bank. She’s likely continuing to raise impressive sums this quarter, which she can put toward a Senate campaign committee, if and when she makes an announcement. 

The wait-to-announce strategy could also be at play in Pennsylvania, where GOP Reps. Lou Barletta and Mike Kelly, a member of the Ways and Means Committee, are contemplating challenging Democratic Sen. Bob Casey.

And in Michigan, Rep. Fred Upton, the former chairman of the influential Energy and Commerce Committee, now an Energy subcommittee chairman, may be biding his time before announcing a challenge to Democratic Sen. Debbie Stabenow. 

Lawmakers from both parties do this. But because the 2018 Senate map puts Republicans on offense, there are more GOP House members expected to launch Senate bids.

On the Democratic side, Arizona Rep. Kyrsten Sinema has been toying with challenging GOP Sen. Jeff Flake. But she’s been coy about her intentions, only saying that she’s “currently running for re-election.” A member of the Financial Services Committee, Sinema ended the first quarter of this year with $2.8 million.

Raising PAC money is far from candidates’ only consideration about when they make their announcements.

And sometimes, it’s less of a factor. 

West Virginia Rep. Evan Jenkins, a member of the Appropriations Committee, is the only House member to have already announced he’s running for Senate.

But he’s likely to face a contentious primary against a statewide-elected official before he gets the chance to challenge Democratic Sen. Joe Manchin III.

“We took into account the reality that you’re leaving PAC dollars on the table the earlier you announce, but we thought it was important to get out there and start introducing Evan to parts of the state where he was less known,” a Jenkins campaign adviser said.

“It’s certainly a trade-off, but in our case, it was one worth making,” the adviser said.