Astrologers did their best to fight back.
Petrus Antonius de Magistris Galathei (1614-75) published a treatise arguing that the bull of Sixtus V had actually been directed only against superstitious astrologers, and that there were certainly areas of astrology that should be permitted to flourish.
This was so; but a combination of the temper of the time and serious reconsideration of the basis of astrology made it more difficult for young students to accept old ideas, and even sometimes forced those formerly devoted to astrology to reassess their position.
Tommaso Campanella (1568-1639) is a case in point. This considerable Renaissance philosopher repeatedly asserted his acceptance of astrology, and even went so far, during his long imprisonment for plotting to free Naples from Spanish tyranny, as to write to Pope Paul V asserting that he was prejudiced against him for astrological reasons! Many other astrological allusions, arguments and predictions issued from his prison cell.
He wrote six or seven books on astrology, asserting that the influences of the planets were physical, and that astrology was therefore a proper subject for the most religious scientific man to study.
He also, rather rashly, disputed the bulls of Sixtus and Urban, arguing that religion should not prohibit proper scientific experiment and discussion, that certainly astrologers should not be treated more harshly than heretics, and that it was quite improper to prohibit not merely forecasts of future events but even suggestions that this or that might happen - proper conjecture, in other words.
However, in the end Campanella agreed that a papal bull, as such, was a papal bull, and should be obeyed, and even went so far as to agree that astrology was not in any real sense a science - though none the less susceptible of scientific study.
Such publications as the Apologia in which Campanella recanted his former opinions did nothing to bolster astrology's reputation against the mounting opposition. This was chiefly directed against the fiercer idiocies of the subject; still, no one denied that the Sun, Moon and planets had an effect on terrestrial matters, and even on men's lives and characters. But more and more it was disputed that there could be any prediction on the basis of planetary positions and movements. Some of the polemics directed against astrologers were not only intensely argued but argued at length.
Alexander de Angelis, of Spoleto, head of the Jesuit College at Rome, published in 1615 no fewer than five books against astrology.
It cannot be said that new astronomical knowledge actually added a great deal to the force of his arguments, which on the whole were yet again rehashings of old ones; the added force came from a new temperamental attitude rather than anything else - an attitude affecting scholars and scientists rather than the man in the street.
http://www.meta-religion.com/Esoterism/Astrology/success.htm