Pat's mistake is that he went the 3rd party route, and 3rd parties simply cannot have an impact in this country. The design of our political system only allows for 2 major parties. Hence the only way to get anywhere is to work from within the parties. Unfortunately, immigration restrictionists haven't been doing this, Tom Tancredo being a notable exception.
You have to factor in that Pat was effectively kicked out of the GOP when he could not do a platform speech (like Keyes was this time, only Keyes doesn't realize it yet). Pat was blamed that his 1992 speech, essentially about the same topic as this thread, was blamed for the defeat of the GOP.
I think Pat knew a third party cannot possible raise the funds needed to win but he hoped to be in the debates to bring this and other ignored issues to the table.
As for working with the party, remember Bobdole would not even read the platform prepared by the grass roots. If a voter cannot even move the pile, I say let a third party be the spoiler, the message might eventually register.