Without a doubt Flake has the most pro-mass immigration record. He has a career C rating from NumbersUSA, but he has an F- on amnesty, chain migration, and increasing legal immigration. Flake sponsored or voted for amnesty six times. He has often taken the lead being the primary sponsor with Luis Gutierrez(D-IL) of the STRIVE Act in 2007. (The Strive Act would have granted amnesty to virtually every single illegal alien in the country. Additionally, it would have created a massive new guest worker-program that would allow 400,000-600,000 additional foreign workers and unlimited spouses and dependents to sign up for a six year visa during which time they could apply for permanent residency.) Flake opposed Arizonaâ€™s Proposition 200 and SB 1070, although he claimed to be against Obamaâ€™s subsequent lawsuit...Flake is already cognizant that this record will be a huge liability in the Republican primary, as evidenced by the fact that he voted against the DREAM Act. But as of yet, he has not been willing to do a complete McCain-style 180 on the issue.
Arizona Senate candidate flip-flops on immigration, by Catalina Camia, USA Today, Mar 23, 2011.)
And also to patriotism.