And we have the E-Verify system for employers to check the legal status of job applicants. It's working well after initial glitches, and in states with high E-Verify usage, like Arizona, illegal numbers have declined.
Source of illegal immigrants. Nearly 60 percent of illegal immigrants come from Mexico, with which we share a 2,000-mile border. But net migration from Mexico appears to have been zero since the housing bubble burst in 2007.
We don't know whether it will resume again. But we do know (as we didn't in the decade after our free trade agreement) that Mexico's economy can grow faster than ours, as it is now.
There were potentially significant differences between what Obama and Rubio said Tuesday.
Obama wants a faster path to citizenship for illegals. Rubio insists that legalization only be triggered when enforcement is strengthened.
Putting together a comprehensive bill requires trade-offs and compromises. Obama's 2007 Senate votes for what John McCain and Edward Kennedy called killer amendments helped defeat an immigration bill when the political stars seemed more in alignment than they do today.
Obama now could demand provisions Republicans won't accept and blame them for killing reform. It depends on whether he wants a political issue or a law.