The first was immigration reform and the second was Obamacare.
Talk radio changed the debate recently and focused on Mexican immigrants who walk across the Southern border. The argument was that as long as we don't control the border, we can not discuss the level of acceptable immigration. That argument was a winner. In the past week, regarding Arizona, 2/3rds of Americans expressed the 'close the border' argument and agreed with it. The 'close the border' argument was helped by the 9/11 Islamic terrorist attack.
Talk radio also made two points about the Obamacare debate. Now 2/3rd of Americans can express and agree with the talk radio position: (a) Obamacare is too expensive for the government and will create massive debt. (b) Obamacare is bureaucratic and will consequently not save money.
Those two points are understood and accepted by the overwhelming majority of Americans. They will not be forgotten come November 2nd because they are points raised and won in a year-long argument. There is a subset of Americans, maybe 40% of voters, who also believe that the Obamacare legislation was passed against the will of the people.
Talk radio won two arguments and will probably win more in the future.