WASHINGTON — The presidential election, lawyers and scholars agree, will offer voters a choice between two sharply different visions for the ideological shape of the nation’s federal courts. Senator John McCain of Arizona, the presumptive Republican nominee, has already asserted that if elected he would reinforce the conservative judicial counterrevolution that began with President Ronald Reagan by naming candidates for the bench with a reliable conservative outlook. Senator Barack Obama of Illinois has been less explicit about how he would use the authority to nominate judicial candidates, but he would be able to - and fellow Democrats certainly expect him to - reverse or even undo the current conservative dominance of the courts. Both have been resolute soldiers in their parties’ political wars over judicial nominations during the last several years. While Mr. McCain has supported President Bush’s judicial nominees, including John G. Roberts Jr. as chief justice of the United States and Samuel A. Alito Jr. as an associate Supreme Court justice, Mr. Obama opposed those nominations and favored Democratic filibusters to block many Republican nominees deemed too conservative. Senator Hillary Rodham Clinton of New York, who remains in the Democratic race, has similarly opposed […]