http://en.wikipedia.org/wiki/Executive_Order_9066
I don't think FDR is under the same pressure to defend the home coastline. The Pacific war is going better and he has done something about all the sinking ships on the east coast. If this still goes ahead, it might be used in a narrower way. To prevent lights on the coast, allow manoeuvres, beef up port security and to site coast watches rather than to intern US citizens with Japanese/Korean ancestry. Opposition from JE Hoover and Eleanor might prove just that bit more convincing.
Astrodragon is right to leave 9066 as is.
The factors involved had nothing to do with "invasion dangers". After, the Nisei of Hawaii were untouched, right? And rest assured, if the Nisei had represented 1/4 of the population of California, as they did in Hawaii, THEY wouldn't have been touched either. Expulsion did not occur until long after any "threat" of invasion had ebbed. The factors behing 9066 were two-fold:
1) Maintaining control of the US House of Representatives in the 1942 Off-year elections. This was FDR at his absolute worst, his absolute coldest. Even his greatest champions do their damndest to gloss over 9066.
2) It was about the money to be had by greedy speculators and evil politicians (but I repeat myself) who made a financial and political killing by feeding the racist hatreds and fears of Whites as well as making a fortune by buying up Nisei property at bargain basement prices. TWO future California governors made their start in politics AND made their personal fortunes in this travesty. Pat Brown-D (Jerry Brown's father!), and Earl Warren-R.
Judging by Earl Warren's later career as Chief Justice of SCOTUS, he must have been suffering from a delayed conscience.
The only justice the Nisei ever got against Pat Brown was political. After humiliating Richard Nixon in the 1962 California gubernatorial election, Brown basically just "mailed in" his re-election campaign in 1966. Only to discover three weeks before election day that his dark horse political unknown Republican opponent's "door-to-door" campaign had put him within striking distance. So, three days before the election, Brown told a press conference: "You know, Lincoln was shot by an actor." He really said this. In California.

I don't think he said this on the corner of Hollywood and Vine, but...
Dark horse candidate and washed up actor turned Governor Ronald Reagan.
And no doubt, lots of saki being drunk that election night.
