What is the connection between U.S. Sen. Kay Hagan and acclaimed U.S. tennis player John Isner?

Both come from Greensboro, but it is more than that.

Isner is known for his three-day 2010 Wimbledon match against French tennis player Nicholas Mahut. Isner won in the fifth and deciding set, with no tiebreaker, 70-68.

As painful as Hagan’s recent loss must be to her and her supporters, it is just the latest game in a long struggle between conservative and liberal or progressive political forces in North Carolina, in which each side has won and lost many times.

Until the 1970s, conservatives and liberals fought their battles in the Democratic primaries. Since then, conservatives have been moving to the Republican ranks.

This epic political tennis match between conservatives and liberals began with the 1948 Democratic gubernatorial primary, when the populist and unapologetic liberal commissioner of agriculture, Kerr Scott, upset the establishment and conservative candidate, Charles Johnson.

Scott’s victory seemed to signal a permanent shift in our state’s political orientation.

However, establishment conservatives came roaring back in 1950, when the more conservative Willis Smith defeated liberal Frank Porter Graham in the Democratic U.S. Senate primary. In 1952, conservative William Umstead defeated Scott’s candidate in the gubernatorial primary, seemingly assuring the reestablishment of the conservative tradition.

But in 1954 Scott won election to the U.S. Senate. This liberal team, now preferring to call themselves progressive, continued winning when Terry Sanford beat Beverly Lake in the 1960 Democratic gubernatorial primary run-off.

Momentum shifted again in 1964, when the Scott-Sanford wing’s gubernatorial candidate Richardson Preyer lost to more conservative Dan Moore, signaling a shift back to establishment conservatism.

Progressives came back in 1968 when Kerr Scott’s son, Robert, was elected governor.

Only four years later the conservative team, now operating within the Republican Party, won a resounding victory, electing Senator Jesse Helms and Governor Jim Holshouser, seemingly moving the state towards long-term Republican dominance.

That tide reversed in 1976 when Jim Hunt became governor and gained reelection in 1980. It reversed again in 1984 when Helms beat Hunt in the U.S. Senate race and Jim Martin was elected governor.

In 1986, Democrats came back with Terry Sanford’s U.S. Senate victory over Jim Broyhill.

Republicans took back momentum with Jim Martin’s reelection victory in 1988 and maintained it in 1990 as Jesse Helms beat Harvey Gantt in the U.S. Senate race.

In 1992 Hunt’s winning campaign for governor would have given progressives cause to celebrate had it not been for Lauch Faircloth defeating Sanford in the U.S. Senate contest.

In 1994, riding on a national wave of disapproval of the Clinton administration, Republicans took charge of the state’s house of representatives and asserted that their permanent takeover was on the horizon.

However, in 1996, Democrats came back with Hunt’s reelection, followed by a 1998 John Edwards victory over Faircloth in the race for the U.S. Senate and Mike Easley’s win in the 2000 gubernatorial election.

Republicans came back in 2002 as Elizabeth Dole beat Erskine Bowles in a high-profile U.S. Senate contest and in 2004 with Richard Burr’s U.S. Senate victory.

In 2008, Barack Obama’s, Hagan’s, and Beverly Perdue’s wins suggested that North Carolina had made a permanent shift toward the Democrats.

In 2010 Republicans won control of the legislature and the power to redistrict and assure control indefinitely. With victories in 2012 and 2014, they have good reasons to celebrate.

But the political tennis match is far from over.

Kay Hagan’s strong showing in a Republican year should give Democrats hope.

Ask John Isner.

Winning one game, or even two in a row, does not necessarily mean a win in a long tennis match – or in a struggle to gain long-term dominance of a state’s politics.