Why has it been difficult for so many US faith leaders to condemn Donald Trump? As someone who believes that faith perspectives have a role in political discourse, I have been depressed by the reaction of many American religious leaders — particularly Christian ones — to the prospect of a Trump presidency.Trump's policy positions that fly directly in the face of Christian values are well documented. They include his anti-immigrant, refugee and Muslim stances, as well as his denial of climate change, disregard for the poor and fuelling of racist sentiment.Despite this, a number of prominent Christian leaders, including Jerry Falwell Jr., James Dobson and Ralph Reed have warmly endorsed Trump. Others have simply turtled and hoped that he would go away.There is little mystery as to why so many religious leaders have lost their voices: abortion.Trump's pro-life stand (despite having claimed the opposite in the past) has prevented many faith leaders from attacking him. In their eyes “life issues” are non-negotiable and the new president will be charged with filling at least one, if not several, vacancies on the Supreme Court. For many, Trump's promise to fill those with pro-life judges eclipses his anti-Christian positions.Charles Chaput, the outspoken Archbishop of Philadelphia who has never feared openly attacking the position of pro-choice politicians in the past, has stated that both candidates for president are equally flawed. And although he has noted that Trump's “defective ethics” and “bombast and buffoonery make him inconceivable as president,” in almost the same breath he reminds Catholics that in considering their voting decision the “right to life undergirds all other rights and all genuine social progress.”Regardless of my personal thinking about abortion and public policy, I respect those who see it as an important political issue. But making it the dominant single issue in any campaign is extremely dangerous, and the current situation in the United States illustrates this point in spades.A “life ethic” has to be about more than abortion. It hears the cries of all who are suffering — the poor, the marginalized and the outsider. It's something that I think about every time I hear Trump's crowds cheer as he attacks Syrian refugees in his speeches.Taking issue with Archbishop Chaput's position on Trump, for example, the Catholic commentator John Gehring pointed out in Commonweal Magazine that Chaput “somehow manages to never mention that Trump has demonized Mexican immigrants as 'rapists,' branded all Muslims as suspicious, boasts that he doesn't ask God for forgiveness, embraces torture, intimates violence against his opponent, and clashed with Pope Francis over immigration.”A life ethic also worries about the future of our planet. Yet in the light of their Church's renewed interest in environmental issues, why have there been so few Catholic voices challenging Trump's claims that climate change is a hoax and his promise to cancel US participation in the Paris Agreement on climate change? As Pope Francis put it, “You are called to care for creation not only as responsible citizens, but also as followers of Christ.”And you have to hand it to Pope Francis. He hasn't been afraid to take on Trump's policies directly, particularly when it comes to his ludicrous idea of building a wall on the border with Mexico to keep out migrants. Although vowing to keep out of the US election, the Pope pointed out that: “A person who thinks only about building walls, wherever they may be, and not building bridges, is not a Christian.”And then sex came along.The release of Trump's thoroughly offensive 2005 musings about women captured on a live microphone set off a firestorm. Many in the religious world suddenly came around. While some continued to support Trump, 700 female Christian leaders condemned his misogyny in an open letter, while several thousand students at Liberty University, which claims to be the largest Christian University in the world, condemned its president, Jerry Falwell Jr., for continuing to stand behind the candidate.No one is arguing that Trump's bragging about sexually assaulting women was not a serious matter — although it was hardly surprising based on past statements. But where were these same voices of condemnation when he denied climate change, incited racial hatred or attacked refugees?It is important to note that not all Christian leaders have shied away from confronting Trump. They have understood the importance of avoiding a one-issue campaign: Faith leaders like Russell Moore of the Southern Baptist Convention who, as early as last May, attacked the Trump campaign for its inherent racism and anti-immigration policies. He noted that: “The man on the throne in heaven is a dark-skinned, Aramaic-speaking 'foreigner' who is probably not all that impressed by chants of 'Make America great again.' ”In response, Trump tweeted that Moore was “A nasty guy with no heart.”John Milloy is a former MPP and Ontario Liberal cabinet minister currently serving as the co-director of the Centre for Public Ethics and assistant professor of public ethics at Waterloo Lutheran Seminary, and the inaugural practitioner in residence in Wilfrid Laurier University's Political Science department. He is also a lecturer in the University of Waterloo's Master of Public Service Program.  John can be reached at [email protected] or follow him on Twitter @John_Milloy.