First, enforce immigration law

During the two weeks that the Senate debated a "grand bargain" immigration bill – and then gave up last Thursday – America had to absorb an estimated 28,000 more illegal aliens. That massive rate of lawlessness is just the reason the Senate should make a second try at reform soon.

Among the chief reasons the bill failed is that it would have reduced the flow of illegal immigrants by only a quarter, according to the Congressional Budget Office. Many senators simply forgot that the initiating impetus for reform began with the post-9/11 drive to better guard US borders and to make sure Americans feel safe once again in welcoming (legal) immigrants.

The Senate got tangled up over many ancillary provisions, such as how to continue providing inexpensive, legal immigrant labor to business or whether to give tax money to newly legalized immigrants. The bill, a careful compromise put together by 12 Republican and Democratic senators, was becoming burdened by an endless stream of amendments, many to simply score political points with key special interests or big donors.

Another reason for the Senate logjam was strong public doubt over a key provision to offer a pathway to citizenship for the estimated 12 million illegal immigrants. The penalties to be imposed for breaking the law before granting citizenship were seen as too weak, and many thought they amounted to amnesty. (The bill imposed fines and fees of more than $9,000, heads of households would have needed to "touch back" in their home country to apply for legal entry, and applicants would have had to learn English.)

That unease over rewarding outlaws with US citizenship touches on the most difficult balancing act for immigration reform: If the penalties are too stiff, illegal immigrants will not come forward and will remain underground, eroding respect for the rule of law; if they are too weak, there's little disincentive for millions more would-be immigrants to keep crossing the border or for those arriving with temporary visas to overstay illegally – also eroding rule of law.

To get around that problem, the "grand bargain" bill tried to put enforcement first. A digital checking system was set for employers to verify a worker's legal status while beefing up enforcement at the border with more agents, more effective electronic detection, and longer fences. Other provisions in the bill would not have kicked in until that system was in place.

But Congress still faces a huge credibility gap. Another "grand bargain" law passed in 1986 promised border enforcement and a crackdown on employers while granting an easier amnesty. The illegal migrants got their amnesty (helping to lure more illegals) but the federal government didn't deliver on enforcement.

To make its case to skeptical Americans, the Senate needs to pass a bill simply aimed at enforcement, hope the House passes it, and then await the reality check on its outcome. It may take a few years of effective enforcement – not just creating the bureaucracy for it – to reclaim the border and keep employers honest.

The initial task in defining who can be an American should be easy: First, obey US law. Senators should reassert their own Americanness by making sure the laws are obeyed at the border and in the workplace.