Hayworth lost for a number of reasons, but immigration wasn't one of them. Mitchell tried to out tough Hayworth on immigration issues. Hayworth lost because of redistricting and an alleged scandal involving his wife on his campaign payroll. I have a home in Scottsdale that was formerly in Hayworth's district.
Allen could have been stronger on immigration issues. Many of us advised him to do so, but he tried to be too politically correct. He could have garnered more support in NoVA if he had done so. The "macaca" remark that the WP kept going for almost two months on a daily basis was the difference along with a poorly run campaign. He should have won going away.
My congressman (Walberg) was endorsed by the Minuteman PAC and won in a district with a fairly high number of American hispanics. Not only that he beat a RINO who was personally endorsed by John McCain and supported by lots of democrats. That sleazeball Schwarz announced a write in campaign less than 48 hours before the election in an attempt to pull votes from Walberg.