Such a happy scene: Republican senators grinning next to Democratic senators as though the debt-ceiling crisis, Obamacare and Sarah Palin never happened. The unifying event is a bipartisan plan to reform the immigration laws, which definitely need fixing.

And recall President Obama’s heartfelt praise of Alan Aleman, an excellent young man, brought to the United States as a child, who “felt American in every way – and he was, except for one: on paper.” Recently made a legal U.S. resident, Aleman is studying to become a doctor and may join the Air Force. Good luck to him.

What could possibly be wrong with all this smiling? It’s the concern that, amid the joy, the interests of American workers will go unnoted. Obama raises some such suspicions with his call, contrary to the Senate plan, for starting the march to citizenship for millions of illegal immigrants before the border is secured and visa tracking installed. That’s not being helpful.

Obama isn’t entirely wrong. He has earned some trust as the first president in decades to actually enforce the ban on hiring undocumented workers. Thanks to these efforts, plus a weak economy and lower Mexican birthrates, illegal entries are way down. But his rush to legalize before an enforcement system is in place evokes failed deals past. Papers are going to have to matter.

Here’s the bigger problem: Republicans indulge businesses wanting low-cost labor. Democrats cater to Latino activists. Chastened by their recent dismal showing among Hispanic voters, many Republicans want to erase memories of racially offensive remarks by some in their party.

But missing from this group picture is the ordinary American worker, whether native born or legal immigrant, besieged on all sides by automation and global competition. Thus, smiles turn into smirks on reading this ominously vague language in the Senate plan:

“Our proposal will provide businesses the ability to hire lower-skilled workers in a timely manner when Americans are unavailable or unwilling to fill those jobs.”

Since farm workers are covered elsewhere, what jobs are we talking about? Short-order cooks? Motel cleaning staff?

Low wages can account for unavailable and unwilling workers. Labor shortages are traditionally cured by higher pay, whether the job involves brain surgery or washing dishes. The law of supply and demand applies to labor as well as to oil.

The Senate plan would redesign the immigration program to favor workers with needed skills. Makes great sense – but even at the top of the skill chart, we still have a domestic workforce to protect.

Educated workers have been displaced by immigrants coming through the H-1B visa program for foreign tech workers. Ron Hira, a professor at the Rochester Institute of Technology, complained to Computerworld that the Senate plan “greatly expands a deeply flawed guest worker program that takes away job opportunities from American workers and undercuts their wages.”

Yes, let’s admit more immigrants with advanced science and math degrees, but not lose sight of this: Draining the world’s educated class as an alternative to creating one on our own soil is lazy and disrespects the American people.

The above are questions more than complaints. The senators have done a generally good job of pairing an effective system for enforcing the laws with an amnesty for illegal immigrants. Some may recoil at the notion of another amnesty or any amnesty, but most might go along if they believe it’s the last one.

The time has rarely been riper for comprehensive immigration reform. Obama should back off trying to rush the parade to citizenship. The election is over. In the meantime, let’s fill in the blanks on those so-called labor shortages. American workers belong at the table, too.