Bernadette Brady, in her book ‘Predictive Astrology’, makes a difference between:
1. progressive aspects with the radix and
2. progressive aspects with progressive positions.
She mentions that radix independent progressions (2) come from the heart, while the radix dependent progressions (1) reflect a desire with willingness to compromise.
I think that the combination of the events and the natal chart and progressions of former Dutch vice Prime Minister Wouter Bos are the perfect combination to show how this theory 'works' in real life. Yesterday Wouter Bos had a press conference and he announced that he will leave politics to dedicate himself to family life. He also said that he had been considering this for long, since 2007.
In 2007 his progressed Sun was conjunct natal Uranus, a radix dependent progression (1). That is when the desire started to change the way that he wanted to go on in life.
In 2010 (right now) progressed Sun is conjunct progressed Uranus, a radix independent progression (2). That is the moment of real change, the moment of the decision.
The conjunction of Sun and Uranus in progression is the reflection of the starting moment (conjunction) of a new (Uranus) lifestyle (Sun).
Here is the chart with progressions. The progressed Sun is in the 6th of Virgo, just like progressed Uranus is. Uranus is in the 3rd degree of Virgo in the radix. Uranus is dispositor of the Midheaven and in the Placidus 4th house.
Of course there were more transits and progressions to accompany this major decission, like indications for emotions and a goodbye and an important transit of Saturn opposition progressed Midheaven that will perfect later (when election time is over and when he really has stepped back).