When is it right to exploit racial or ethnic fear to fight a political campaign? Never.

But that’s what the Maine Democratic Party has done in a pair of mailings this week that use crude stereotypes to play on people’s fears of the Chinese. This should not be tolerated.

The subject of the mailers is independent gubernatorial candidate Eliot Cutler and criticisms of his work as a lawyer who did business with companies based in China.

Attacking candidates is fair game as long as it is done fairly. Fights are fights but we have a right to demand they be fair fights.

Cutler is fighting back against the conclusions the mailings draw, and we believe voters are smart enough to recognize a piece of political propaganda when they see it. They realize that they are just getting one side of the story — a potentially distorted one at that.

But in order to sell their point, the Maine Democrats have chosen to take a very low road.

In one mailing there is a picture of a fortune cookie with a message that tells voters Cutler would send their jobs to China, associating the local Chinese restaurant staple with financial competitors overseas.

The other shows a made-up help-wanted ad written in Asian characters, telling voters that if Cutler wins “Mainers might as well learn Chinese.”

This is not political discourse. It is an attempt to demonize a group of people and hurt a rival by associating him with that group. This could do more than affect the outcome of an election; it could fuel distrust in our communities.

How should Chinese-American Maine Democrats feel about getting this literature in their mailboxes?

In this time of economic insecurity, they now have good reason to suspect that some of their fellow Democrats believe they are stealing jobs.

Democratic nominee Libby Mitchell has pointed out that her campaign does not control these ads. The party operates independently from her campaign and by law is prohibited from coordinating with her.

That may be true, but she’s not prohibited from speaking out against them.

If a radical fringe group put out a mailing like this, we would be angry. For a major political party to do it, especially one that claims the legacy of the civil rights movement, we are outraged.

In the last week of a campaign, political operatives are under stress and capable of making bad choices.

That looks like what happened here. Now that the damage has been done, the people behind these mailings should do the right thing — repudiate these messages and apologize.