My dad turned out to be a Hagee fan the last couple of years of his life. He sent me some of his writings.
In one of the books (either In 'Defense of Israel' or 'Jerusalem Countdown') he said that the gospel does NOT need to be preached to Jews. "They have their own covenant."
I know for a fact that many Messianic leaders have tried to engage them including our own Rabbi Dan Juster, director of Tikkun International. He has blown them off at every attempt.
While he has not come out and said so, his very public relationships with orthodox Jewish leaders like Rabbi Arieh Scheinberg and Rabbi Selwyn Franklin who HATE Messianics is probably a big factor. He wants in with traditional Jews for some reason (and it is NOT to spread the gospel) and we stand in his way. If he is friendly with us, he cannot be with them as they will stay far away.
From the wiki article on Hagee:
The Christian Research Institute (among others) has strongly criticized Hagee's recent book, In Defense of Israel (2007), for apparently arguing that Jesus did not claim to be the Messiah for the Jews, only the Savior for the Christian Church, and therefore, that attempts should not be made to convert Jews.
That is what I read as well.