Original sentence: (The party is now viewed by some to be slightly right-of-centre much like the United States Democratic Party).One spin-doctoring technique (standard across the main parties for many years) used was getting supporters, or people who generally agreed with the party to put their name to pre-made letters and send them into their local newspaper
Edited sentence: One spin-doctoring technique used was getting supporters, or people who generally agreed with the party to put their name to pre-made letters and send them into their local newspaper.The party is now slightly right-of-centre much like the United States Democratic Party