With as many as eight states expected to host hot races for both the Senate and the governorship next year, the question arises: Does doubling a state’s political excitement tend to join the two contests at the hip, or does it drive them apart?

The answer, as so often is the case in politics, is: “A little of both.”

A Roll Call analysis of Senate and gubernatorial races since 1996 found that whenever a state holds two reasonably competitive contests in the same cycle, the likelihood of the same party winning both seats is about 2-to-1. And when at least one of those seats is open, the likelihood rises to 3-to-1.

This almost certainly has something to do with state parties’ coordinated get-out-the-vote campaigns, which in a good year can energize strong partisans to vote a straight party ticket. For instance, Georgia’s state GOP, led by Ralph Reed, fanned a grass-roots brushfire in 2002 and ended up not only ousting Democratic Sen. Max Cleland but also, in a genuine stunner, knocking off Gov. Roy Barnes (D) and seizing the state Senate.

Other times, fate intervenes to help one party claim both seats. In 2000, the late Missouri Democratic Gov. Mel Carnahan, who had died in a plane crash two weeks earlier, nevertheless won a Senate seat, possibly aiding the victory by the Democratic gubernatorial nominee, Bob Holden. And in 2002, Minnesota Republicans Norm Coleman and Tim Pawlenty won a Senate seat and the governorship, respectively, in the wake of a raucous memorial service for the late Democratic Sen. Paul Wellstone.

Even when the parties battle to a split decision, the composition of the statewide ballot can matter. In Arkansas in 2002, Democratic gubernatorial candidate Jimmie Lou Fisher didn’t win, but she far exceeded expectations and managed to motivate female voters and liberals to go to the polls, where they likely aided the Senate victory by moderate Democrat Mark Pryor, said Jay Barth, a political scientist at Hendrix College.

Yet despite such anecdotal evidence, campaign veterans say there are at least as many factors that drive Senate and gubernatorial races apart.

A big one has to do with the issues discussed in the campaigns. While some topics such as taxes and spending tend to resonate equally in federal and state races, the most hotly debated issues tend

to be divergent, said GOP consultant Terry Nelson.

Senators tend not to hear much about local school funding and road projects; governors almost never have to deal with foreign policy. And real-estate developers and other local businesses often help drive the agenda in state races, thanks to deep-pocketed donations and independent issue ads. National races, by contrast, tend to be shaped by a much broader array of forces.

“Because of the national dialogue coming from Washington, federal races are now more homogenized than they ever used to be,” said New Hampshire-based Democratic consultant Thomas Oppel. State races, by contrast, tend to operate by their own rules, he said.

Voters are savvy enough to know the difference between what governors and Senators do, added Ohio-based Republican strategist Mark Weaver. In “right track-wrong track” polls, Weaver said, “it’s not uncommon for voters to think that the country is on the right track and that the state is on the wrong track, or vice versa. It tells us that voters harbor different feelings about the national and state governments.”

Another factor pushing campaigns for federal and state offices apart is the potential for conflicts, be it over personality, strategy or access to the state party’s resources.

“Unlike in the past, there’s no party boss,” said one Democratic campaign veteran. “So a gubernatorial candidate will have his consultants, and the Senate candidate will have his, and they may be going in different directions.”

Indeed, the degree of cooperation between campaigns depends heavily on whether each campaign sees it in their interest to team up. Often, there’s no compelling reason to do so.

In the heat of a race, Senate and gubernatorial strategists may have a bad case of tunnel vision, said Patrick Davis, a veteran of three cycles at the National Republican Senatorial Committee.

“Sometimes I had to watch the evening news to hear what happened in the governors’ race that day,” Davis said. The tendency for local media to cover each race with different reporters widens that chasm, he added.

So what does all this mean for 2006, when at least three states (Maryland, Minnesota and Ohio) are expected to have two strongly competitive contests, and another three (Florida, Pennsylvania and Michigan) will feature at least one hot race and possibly a second?

In Ohio, an open governorship and the endangered seat of GOP Sen. Mike DeWine happen to coincide with a meltdown within the state Republican Party, making the state strong a candidate for a Georgia-style Democratic sweep. In the “purple” state of Minnesota, many analysts expect a barnburner to succeed Democratic Sen. Mark Dayton and a vigorous re-election contest for Pawlenty.

But the most compelling pair of contests next year will probably be in Maryland. In the staunchly Democratic state, Republican Gov. Bob Ehrlich is seeking a second term and his lieutenant governor, Republican Michael Steele, is drawing national attention in his all-but-certain bid for an open Senate seat.

The Maryland contests could well be decided by whether the Democrats can link Ehrlich and Steele to a Republican president and Congress that are distinctly unpopular in the state.

Republicans, for their part, can make a strong case that Ehrlich has, like any incumbent governor, established his own record to run on. And Steele may be able to overshadow the torrent of national Republican support — including an appearance by presidential adviser Karl Rove — by upending the state’s political and demographic calculus, since he’s running as a black Republican.

“Maryland is a case where, for compelling reasons, the Republican candidates will not want to run together,” acknowledged one Republican consultant. “Steele will not want to deal with some of the problems the Ehrlich administration has, and Ehrlich won’t want his race to be nationalized.”

But despite Steele’s high-profile support from the national GOP, Democrats may not be able to paint Ehrlich with the same brush.

“I don’t see how you nationalize the governor’s race,” said Kevin Igoe, a lobbyist and former state GOP official in Maryland.

One of the most intriguing variables in next year’s dual Senate-governor races is the impact of the Bipartisan Campaign Reform Act.

One Democratic source noted that because BCRA imposed strict limits on certain types of federal campaign money, gubernatorial campaigns in states that have relatively loose campaign-finance laws could become the true cash cows of the 2006 cycle, and a governor’s campaign team could become a serious kingmaker by lavishing get-out-the-vote funds and other resources on other races.

“The more sophisticated state parties will figure out a way to complement each other,” the Democrat said. State entities “often have a lot more options in raising and spending money, and in a lot of states, that will put them in the driver’s seat.”

And that’s a good reason for those afflicted with Potomac fever to keep their state contacts fresh. After all, it’s often the gubernatorial race — not the Senate contest — that attracts the lion’s share of media attention and voter interest. In the words of one Democratic operative, voters know that “a Senator is one out of 100, but the governor influences everyone’s life.”