In the past few months, three American Catholic bishops have indicated to several ostensibly Catholic politicians that their pro-choice positions are incompatible with their public stance as Catholics. "You have failed to restrict the evil of abortion when the opportunity presented itself," said Bishop Raymond Burke of La Crosse in a letter to Wisconsin state senator Julie Lassa. Bishops in California and South Dakota have taken similar steps against politicians who are publicly Catholic and pro-choice.

The politicians' response has been predictable. "I can't let my religion take precedence over my duties as legislator," says Lassa. "I'm concerned that the bishop would pressure legislators to vote according to the dictates of the church instead of the wishes of their constituents." "The votes I cast are driven by my own independent judgment and conscience, not by a set of marching orders given by any church hierarchy," said U. S. Rep. David Obey, a Democrat who represents Wisconsin's 7th district. (Obey "stopped short of identifying himself" as the recipient of a letter from Bishop Burke, according to the Milwaukee Journal Sentinel, but issued a statement nonetheless.) In reply to a chastising letter by Bishop Robert Carlson of Sioux Falls, Sen. Tom Daschle said, "I have been a Catholic all my life and will remain one."

William Bablitch, a former Wisconsin state Supreme Court justice and a Catholic, summarized the liberal argument. "The doctrine regarding the separation of church and state is well-founded in our democracy for a very good reason," he said. "Certainly the bishop has every right to express his own views to an elected official. But to invoke the moral authority of the church in a threatening way to a legislator seems to cross over a line that has been very carefully drawn and is very well respected in this country."

'In a threatening way?' Let's see what exactly what bishops have 'threatened.' Bishop Burke's letter said that if Catholic legislators continued to vote for bills related to abortion rights, he would "ask them not to present themselves to receive the sacraments because they would not be Catholics in good standing."

How 'threatening' is that, politically speaking?

What the legislators and their supporters don't seem to realize is that, precisely because America does have separation of church and state, bishops can't "threaten" legislators at all. What Bishop Burke and others are doing is not telling legislators how to vote, but how they can identify themselves if they vote in certain ways.

As things stand now, Catholic legislators like Lassa can have it both ways. They can get credit from Catholic voters for their "Catholic" identification, and even for being seen to receive Communion on Sundays. And they can also get credit for their votes from those who support abortion. Now, a few bishops are beginning to say that such legislators can't both defy the teaching of the church and identify themselves as Catholics in good standing.

If the community at large is going to insist that nominally Catholic legislators should indeed be allowed to have it both ways, then it is the bishops' authority that is being undermined, not the independence of lawmakers. And that is what has been happening in our increasingly secular culture.

What is at stake is the right of the Catholic Church to set its own membership rules. Any organization that is denied that right is under attack. Admittedly, the American bishops have contributed to their own difficulties by failing to insist earlier on their right to demand standards of observance from public figures who claim membership in the Church.

As the years and decades have passed without complaint from the bishops, their own moral standing has grown weaker and weaker (a state of affairs only underlined by the recent crisis of pedophilia in the hierarchy). Politicians have in turn grown accustomed to great laxity and indulgence from the hierarchy, and now the politicians have reached the point where they expect it to continue.

Following a recent instruction from the Vatican on the participation of Catholics in political life, the U.S. Conference of Catholic Bishops is taking steps to remedy this situation. The Vatican document said Catholic lawmakers have a "grave and clear obligation to oppose any law that attacks human life." Last month, the USCCB announced it would develop an agenda along the lines already mapped out by Bishop Burke.

Politicians like Lassa who invoke the "separation of church and state" often quote John F. Kennedy's famous speech of 1960: "I do not speak for my church on public matters, and the church does not speak for me." Kennedy also said: "I believe in an America where the separation of church and state is absolute-where no Catholic prelate would tell the President (should he be Catholic) how to act."

But John F. Kennedy also said he believed in a state of affairs in which religious views were not imposed by the nation any more than they were imposed upon the nation. What some commentators now seem to want is precisely a state of affairs in which "the nation" imposes its own consensus on the church.

A final point about Kennedy's speech needs emphasizing. The country at that time was culturally far more in line with the teachings of the Catholic Church than it is today. In 1960, it seemed unexceptional to say that no prelate would tell Catholic lawmakers "how to act." But now we are in a place where the bishops' continued failure to speak out has reached the point of scandal.

One of the most candid comments on this topic was made recently by the late president's brother, Sen. Edward Kennedy of Massachusetts. A reporter with a Catholic journal asked Sen. Kennedy how he could reconcile his voting record with church teaching. Kennedy seemed uneasy, but then he said of the bishops: "It's their problem, not mine." Presidential candidate Sen. John Kerry said much the same thing when he was asked the same question: "If the bishops can't do and won't say anything about that, don't come to me."

In a backhanded way, the Massachusetts senators were on target. If the bishops think it's okay that these two very prominent pro-abortion senators call themselves Catholic and publicly receive Communion, why should the senators have any compunction about doing so?

Obviously, they imply, if there was anything wrong, the bishops would have said something about it by now. But the bishops have not done so. When Sens. Kennedy and Kerry attended the installation Mass for his successor, Archbishop Sean O'Malley, both received Communion.

Now, the bishops may be realizing that their silence has had the effect of undermining the faith. They have been signaling that although certain doctrines are part of the church's official teaching, the Church doesn't take them very seriously in practice.

If bishops think that support for abortion puts immortal souls in danger, they must say so publicly. And if, following public warnings, lawmakers continue to defy the Church, bishops should not hesitate to exercise the power of excommunication.

This power is a separate matter entirely from the exercise of state power. In fact, it is precisely because church and state are separate in this country that such ecclesiastical power can be exercised without fear of entanglement.

In this country--unlike in, say, England--archbishops and cardinals can neither appoint nor be appointed by state officials. And, indeed, they cannot tell such officials how to vote. But they can tell public officials, if they identify themselves as Catholics, that they are expected to observe the rules and teachings of the church. If the Catholic bishops do begin to exercise their right (and rite) of excommunication, there will be a very public uproar. At the same time, the bishops will begin to recover the moral authority that they have so conspicuously surrendered.