Proof that the immigration system does not work is plentiful. It's in the 11 million people living in the U.S. without the legal documents, the farmers whose crops rot in the field because they can't find Americans to do the work, the children in limbo because their parents brought them into the country illegally, the innovative foreign students who come to learn but can't stay to work.

A bipartisan group of senators - including Arizona Republicans John McCain and Jeff Flake - presented their broad outline for changes at a Monday press conference.

President Obama shared his outline yesterday in front of a Las Vegas crowd.

Both plans state broadly that Congress should create a way for those among the 11 million who have no criminal record to pay a penalty and any back taxes and gain legal status. Those who were brought into the country illegally as children should also have a way to become citizens.

Making the visa system more efficient so families aren't separated for years waiting for paperwork to be processed is part of both outlines, as is making it easier for students in science, engineering and technology fields to work legally in the U.S.

Similarly, both state that employers who knowingly hire undocumented workers must be penalized - but that the federal system for checking a person's legal immigration status must be beefed up in accuracy and accessibility.

One roadblock we foresee in the senators' framework is that it makes creating the path to legal status and potential citizenship dependent on "securing the border."

This phrase - securing the border - is malleable and therefore, on its face, unachievable. The Obama administration has already put more officers than ever before along the border, and apprehension figures indicate that the region is more safe, at least on paper, than it used to be.

Yet people still try to cross the U.S.-Mexico border to traffic in humans or drugs - and some succeed. Sealing off any border is impossible. People who are motivated enough by family need or criminal enterprise will always find a way.

The senators' plan calls for creating a commission "comprised of governors, attorneys general and community leaders living along the Southwest border to monitor the progress of securing our border and to make a recommendation regarding when the bill's security measures outlined in the legislation are completed."

Deciding what "progress" means, and pinpointing when the border is secure, will take realism, compromise and understanding of a complex and dynamic border region. We doubt that any individual, much less an elected official, will want to say "yes, the border is secure" for fear that the next drug bust or group of migrants caught will prove the statement untrue.

As these frameworks evolve into legislation, we encourage the senators to drop the secure-border prerequisite. Creating such a trigger will guarantee only that progress on the rest of the package will be stymied, as it has been before.

The senators and Obama each made the point that the country must seize this moment to make changes for the good. The Republicans are motivated by the hope that Latino voters will view efforts in a positive light, and Democrats are motivated by the fact that immigration is a vital issue that was overlooked in Obama's first term.

Improvements will come only if the senators remain steadfast in their resolve and do not sway in the political winds. McCain has clout to offer, but his constituents remember about five years ago when he supported similar legislation only to abandon his position during his run 2008 presidential run.

Flake has also worked on the immigration issue during his time in the U.S. House. Both men are poised to be influential in a way that could benefit their home state and nation.

It is too soon to endorse or condemn either proposal, although we are encouraged by their tenets, and by how similar they are. This could provide the foundation necessary to, at long last, fix problems that have dogged our nation for years.

Arizona Daily Star