Sens. John McCain and Barack Obama must know by now that they can’t campaign for president while skirting one of the most pressing but divisive issues on voters’ minds: illegal immigration.

Last week’s convention of the League of United Latin American Citizens, at which both candidates spoke, reminded everyone that an unavoidable political time bomb awaits the next administration.

The candidates cannot kick this issue down the road or wait for a more politically expedient time to tackle it. No matter what position they take, one voting sector or another will be alienated by their stances.

It appears, though, that they were trying at the convention to tiptoe painlessly through a cactus field.

Mr. McCain, once a leading advocate of comprehensive immigration reform, made clear that he has re-ordered his priorities by saying that border security must come first.

Since securing the border will take years to complete, his plan could delay comprehensive reform indefinitely. He is justifiably nervous about alienating his conservative base, which opposes the reform legislation he once championed.

Mr. Obama was quick to point out Mr. McCain’s switch in emphasis. But attacking Mr. McCain doesn’t necessarily help the Democrat.

He faces pressure from labor unions, which fear that comprehensive reform will open the door to cheap labor and suppress American workers’ wages.

Instead of pledging quick action, Mr. Obama committed himself to enact a comprehensive reform package sometime before his first term ends. Again, that can mean years of waiting.

Both candidates also are trying hard not to alienate the nation’s estimated 7.6 million Hispanic voters, who could easily sway the election’s outcome. Neither Hispanic voters nor anyone else who cares about illegal immigration should let these two avoid offering unequivocal commitments on reform.

This newspaper wants a president who pledges to address comprehensive immigration reform – including border security – without delay.

This package must include tough measures for workplace enforcement, penalties for employers who skirt the law, a guest-worker program that responds to employers’ needs for cheap labor and a pathway to regularization for existing immigrants who come forward and agree to abide by the law.

The candidate who confronts this issue head-on will go a long way toward demonstrating his readiness to lead our nation.

WHAT THE CANDIDATES SAY:

"I have always believed that our border must be secure and that the federal government has utterly failed in its responsibility to ensure that it is secure. If we have learned anything from the recent immigration debate, it is that Americans have little trust that their government will honor a pledge to do the things necessary to make the border secure."

– Introductory quote on John McCain’s campaign web site

Immigration plan includes:

- Help Latin American allies create jobs at home.

- Promote flexible U.S. labor market.

- Emphasize assimilation. Immigrants should learn English, American history, civics and respect for the values of a democratic society.

"The time to fix our broken immigration system is now. ... We need stronger enforcement on the border and at the workplace. ... But for reform to work, we also must respond to what pulls people to America. ... Where we can bring in more foreign-born workers with the skills our economy needs, we should."

– Introductory quote on Barack Obama’s campaign web site

Immigration plan includes:

- Create secure borders.

- Improve U.S. immigration system.

- Remove incentives to enter illegally.

- Bring people out of the shadows.

- Coordinate better with Mexico.