Any veiled support of pork is a risky proposition in a Republican primary—just ask Iowa Senate candidate Joni Ernst, who touted her experience castrating hogs as proof she can cut wasteful spending in Washington. But with Democrats challenging in all three races, proving value to your constituents is still a tried-and-true formula for a general election. Indeed, New Jersey Governor Chris Christie used House Republican opposition to the level of funding for Hurricane Sandy relief as a rallying cry for his reelection campaign.

In a sign the tide has shifted, former Mississippi Governor Haley Barbour offered an unapologetic defense of Cochran's influence bringing home federal funds in a column that ran last week in the Sun Herald. In it, he touted Cochran being in position to chair the Senate Appropriations Committee if Republicans retake the Senate, and highlighted his vote to reopen the government after the shutdown last October. It's not surprising to see Barbour, one of Washington's most imposing power brokers, defend the importance of influence and seniority. But it was unusual for him to do it so publicly—taking the Tea Party on and directing his message to a conservative Gulf Coast audience who has benefited from the federal-recovery largesse.

"Haley's got some balls," said his nephew, Henry Barbour, who is running the pro-Cochran Mississippi Conservatives super PAC. "When a state gets hit by the worst natural disaster in the history of the country, most people understand federal government has a proper role there."

The Mississippi Senate primary, taking place on June 3, is the most consequential test of where the Republican Party stands on the role of federal spending. Even Cochran insiders regard the six-term senator as being in serious trouble, polling around 50 percent with softer support than his tea-party-backed rival, state Senator Chris McDaniel. But his campaign's willingness to embrace the argument that influence and seniority still matters—one that Republicans have shied away from lately—could embolden Republicans to tout their clout, especially after primary season is over.

"The political environment favors McDaniel, and sometimes it's hard to overcome the political environment, one that's sick of Washington," one Cochran ally said. "But as Trent Lott once said, 'Pork is federal spending north of Memphis.' "

All three upcoming races featuring appropriators in tough Senate races—Cochran, Kingston, and McConnell—also share another characteristic. Democrats are aggressively contesting all three seats on Republican turf, and their recruits don't have to be ambivalent about federal spending. Until the GOP landslide of 1994, Democrats retained a congressional stronghold in the South even as the national party drifted left, thanks to their veteran members' ability to deliver money to their home districts. While the partisan makeup has dramatically changed since then, voters still appreciate the politicians with a record of providing to their constituents.