For most people, the bloodshed in Tuscon was a signal to ratchet down political rhetoric and to reflect on why such violence occurs. But for one bishop, it offered an opportunity to attack President Obama's support for abortion rights.The Without a Doubt column Bishop Thomas J. Tobin of Providence wrote in response to the president's speech in Tuscon is a good example of how driven certain bishops are to make the Catholic Church a one-issue church. Bishop Tobin somehow used Obama's Tuscon speech - "his best moment as president" - as an opportunity to write that he is "the most pro-abortion president" ever. He writes that "abortion policy is the prism through which I view everything this president says and does."He is not the only bishop to use this "prism" - a viewpoint that is out of step with the Vatican's.Pope Benedict XVI pressed Obama on the importance of the abortion issue when they met in 2009, and afterward his spokesman noted that Obama said he is committed to reducing abortions. But the pope and Obama also discussed immigration, religious tolerance, the Middle East and other issues. I don't think they could have had much of a talk if the pope used Bishop Tobin's standard and judged each issue through the "prism" of the president's support for abortion rights.When a Vatican spokesman praised Obama's Cairo speech, he didn't view it through the "prism" of abortion. Nor did the Vatican use the "prism" of abortion when it said in a statement that Obama deserved the Nobel Peace Prize for his support for nuclear disarmament and international peace. To do otherwise would lack common sense.