As the city of Portland considers stepping in between anti-abortion protesters and the downtown Planned Parenthood clinic, the watchword should be “caution.”

This is a highly sensitive conflict of fundamental rights — going even a little too far to protect one side could damage the other. That especially goes for the city, but it applies to the protesters and the clinic, too.

As city officials have acknowledged, anti-abortion advocates have a right to protest on public property outside the clinic. That includes picketing, chanting and holding signs, even if the images on them are disturbing. This kind of speech is exactly what the First Amendment protects and it should be treated with deep respect by any government official who does not want to violate the Constitution.

But reproductive rights are also constitutionally protected, according to the Supreme Court, and women cannot be blocked from entering a clinic, or intimidated or harassed, without the law being violated, regardless of whether the protesters think they have good intentions.

Maine has some of the toughest laws in the country protecting clinics like Planned Parenthood from protesters who go too far.

Maine is one of 11 states that explicitly prohibit protesters from blockading a clinic’s entrance. It is one of eight states that ban harassment of clinic staff, one of two that ban harassment by phone.

Maine also has a legal noise limit outside clinics, and authorities can tell protesters to quiet down if they are disrupting the clinic’s work.

The rule should be that the city can only react to what is really happening. If the clinic entrance is blocked, the city has an obligation to make sure the people who want to get in and out can do that. But the city would be going too far if it cleared away protesters who might block the entrance.

The protesters should also be careful. They have a right to express themselves, but not to interfere. They should be respectful of the rights of people who need to access health care, even if they object to one service that the clinic provides.

This may look like a situation where the city has to step in and decide in favor of one side or the other, but it is not.

Both sides should be able to exercise their rights fully. To the extent that city officials can make sure that happens, they will be doing an important service.