It seems clear that neither Obama nor the Dems actually want a solution to the very serious problem of illegal immigration. This issue is far too important to the Dems as both a demagogic bludgeon and campaign issue. The Dems will do everything they can to destroy a realistic and enforceable solution to this problem.
They know that much of what Obama is proposing is a non-starter with Republicans and that is why it is being proposed. They will kill all chances for Rubio to succeed, then as elections near, they will blame Republicans not only for failing, Obama will probably try to end run the issue with an executive order. Democrats can only be viewed as criminal.