Under the gideon ruling why is trial judge required to appoint a lawyer for defendants who claim case are too poor to pay for one

Because, according to Oyez, "The Sixth Amendment's guarantee of a right to assistance of counsel applies to criminal defendants in state court by way of the Fourteenth Amendment."

Gideon v. Wainwright was a milestone lawsuit in the history of the Supreme Court of the United States. In this particular case, the U.S. Supreme Court consistently commanded that states are obligated following Amendment Sixth of the Constitution of the United States to afford a lawyer to defendants in felonious cases who are incapable to afford their lawyers. The lawsuit reached the freedom to counsel, which had been observed following the Fifth and Sixth Amendments to force obligations on the federal administration, by inflicting those provisions upon the states as well.

hello no i dont sorry.