2009 - CDU
2005 - CDU
2002 - FDP
1998 - SDP
1994 - CDU
1990 - CDU
1987 - Greens
1983 - FDP
1980 - FDP
1976 - FDP
1972 - FDP
1969 - FDP
1965 - CDU
1961 - FDP
1957 - CDU
1953 - CDU
1949 - CDU
Why would a right-winger who supported SPD in 1998 not support them again in 2002 ?
Well the reason I see myself supporting the SDP in '98 is not only because of the party's 3rd way centrism and moderation but also as a "it's time to retire Kohl" vote. His government had been in power too long and Germany needed some fresh air, by 2002 there was no longer any such need.
"Let's have left-wingers win elections once every 30 years, just for fun's sake. But only for one term, otherwise they might be tempted to enact left-wing policies."
Actually yeah, now you've got it!
I feel the same way about right-wingers, so no worries.