Note: This page was written by the retired Social Science Librarian, John Henderson
Elected officials have been accused of systematically discounting the opinions of constituents with whom they disagree. Even if they don't disagree, it will be be difficult to sway them to buck their party's position. However, letters and phone calls can and have made the difference, especially on issues that have some bipartisan support. Even if it does not convince your representatives on a specific issue, they need to know you are out there. They well know that people who are active enough to contact them are the most conscientious voters.
Based on advice from Mark Jahnke, who used to work in a US Senator's office as the person in charge of incoming phone calls.
An additional tip is to call during business hours, and keep trying if the line is busy. There have been claims that some elected officials purposefully keep their message boxes full, so no after-hours messages can get through. Some have even been accused of leaving their phones off the hook during business hours. This has not been documented.