As we head into the dog days of summer, Out There presents a column purely for fun: our favorite political streaks.

They don’t have quite the cachet of Joe DiMaggio’s 56-game hitting streak or Cal Ripken’s 2,632 consecutive games played, but for politicos, these mathematically improbable outcomes are still worthy of admiration.[IMGCAP(1)]

The Pennsylvania Governorship. Since the end of World War II, Pennsylvania’s governorship has bounced between the two parties at perfect eight-year intervals. Stranger still, the state has allowed governors to succeed themselves since only 1974, meaning that incumbency helps explain just a portion of the streak.

Historically, the governor of this politically competitive state has been so dominant that it’s been more common for out-parties to muster a strong challenger than it has been for the incumbent to anoint a viable successor, Democratic consultant Larry Ceisler said.

And historically, the state’s periodic economic downturns meant that “governors could rarely go through eight years without a deficit and the subsequent need to raise taxes,” said Franklin and Marshall University political scientist Terry Madonna.

Whatever its roots, the pattern appears to have become self-enforcing. David Patti, president of the pro-business group Pennsylvanians for Effective Government, is convinced that “really good candidates sit out because they think it’s not their year, or donors put up some but not all of the money they could. And that perpetuates the ‘curse.’”

In 2006, Democrat Ed Rendell will have to defend the 60-year-old streak. He’s favored, but Republicans are winning some buzz with three potentially strong candidates — which, compared to recent history, is an embarrassment of riches at this point in the cycle.

North Carolina Senate Seat. Another back-and-forth pattern has emerged in North Carolina. Every six years since the early 1970s, one Senate seat has switched between individuals — and parties.

In 1974, Robert Morgan (D) took an open seat. In 1980, he was defeated by John East (R). East committed suicide while still in office, and in 1986, Terry Sanford (D) won the open seat. Then, in 1992, Sanford was ousted by Lauch Faircloth (R), who in turn was ousted by John Edwards (D) in 1998. Then, last fall,

Richard Burr (R) took the seat Edwards vacated to run for president.

Here, too, the pattern may not be entirely random. Democrats have won the seat in nonpresidential years, and Republicans have won it in presidential years. That makes sense: In North Carolina, higher-turnout years tend to help the GOP, because infrequent voters in the state tend to vote Republican, said Ferrel Guillory of the University of North Carolina at Chapel Hill.

So how did Sen. Jesse Helms (R-N.C.) manage to win five straight terms in the same period? Helms was aided by two GOP presidential landslides — Richard Nixon in 1972 and Ronald Reagan in 1984 — and a high-profile showdown against Democrat Harvey Gantt in 1990 that drove up statewide turnout, Guillory said.

Other Senatorial Streaks. In what easily is the longest streak on our list, Vermont has elected only one Democrat, Patrick Leahy, to the Senate since it was admitted to the union in 1791. In 2006, Independent Sen. Jim Jeffords’ seat comes open, but almost no one expects it to go Democratic, since Democrats are casting their lot with Independent Rep. Bernie Sanders.

Elsewhere, two sitting Senators can lay claim to having represented their state for a good portion of its existence. Ted Stevens (R-Alaska) and Daniel Inouye (D-Hawaii) are both the second of only two Senators to have held their seats since their state was admitted to the union in 1959. Their predecessors? Bob Bartlett (D) in Alaska and Oren Long (D) in Hawaii.

The Dingell Family. This year, Rep. John Dingell (D-Mich.) marks his 50th anniversary in Congress. But his family’s hold on the seat goes back even further: Dingell’s father, John Sr., served from 1933 until his death in 1955. The 72-year Dingell family reign is easily the longest for a continuously held Congressional seat, according to the Congressional Research Service.

“I’m very proud of the fact that my father left me a good enough name to allow me to follow him,” Dingell said.

Speculation is rife about another Dingell eventually taking over. Many believe that Dingell’s wife, Debbie, would be the natural successor. But back home, Dingell’s son Chris, a former state Senator and now an elected judge, is also considered a strong possibility, said Bill Ballenger, publisher of Inside Michigan Politics.

Congressman Dingell is keeping mum.

“People always ask me that question,” he said. “I always say, ‘We have a perfectly good Dingell in the job,’ and just leave it at that.”

New Hampshire’s No-Tax Pledge. Since 1972, when the late Republican Meldrim Thompson originated a pledge to veto any broad-based tax, every winning candidate for governor of New Hampshire, whether Republican or Democrat, has followed suit.

Democrat Hugh Gallen, who defeated Thompson in 1978, took the pledge. But by Gallen’s third term, the state was mired in a budget crisis, and he abandoned the pledge. He promptly lost to Republican John Sununu Sr. — a turnabout that bolstered the pledge’s mystique, said New Hampshire-based Democratic consultant Thomas Oppel.

In New Hampshire, Oppel said, “rare is the political discussion that doesn’t begin or end without raising ‘The Pledge.’”

Arkansas and Open Seats. Next year, when Arkansas Gov. Mike Huckabee (R) steps down, it will mark the state’s first open governor’s seat since 1978, when then-Gov. David Pryor (D) ran for Senate and was succeeded by future President Bill Clinton.

Clinton lost to Republican Frank White after two years, then ousted White two years later. When Clinton became president in 1992, the job fell to Lt. Gov. Jim Guy Tucker (D), who resigned in 1996 after being convicted of fraud. Then-Lt. Gov. Huckabee succeeded him, where he remains.

Odder still, 2006 marks the first time since 1966 that the state’s governor, lieutenant governor and attorney general slots have been open simultaneously, said Hendrix College political scientist Jay Barth. Arguably, the streak goes back even further: In 1966, the sitting attorney general lost in a primary.

Missouri, the Nation’s Bellwether. Since the dawn of the 20th century, Missouri has always voted for the winner of the presidential race — except once. In 1956, the state backed Adlai Stevenson over Dwight Eisenhower.

Why the correlation? Despite all the upheavals of the 20th century, Missouri still represents a microcosm of America, Saint Louis University political scientist Ken Warren said. It’s at a geographical crossroads. Its proportions of minority voters, urbanites, rural voters and union members are similar to the national mean. And the state is politically competitive.

So why did Missouri back Stevenson in 1956? Actually, both Eisenhower-Stevenson races were close in Missouri. Eisenhower, from neighboring Kansas, won with 50.7 percent in 1952, and Stevenson, from neighboring Illinois, won with 50.1 percent in 1956.