Yeah, DC did so much better when its people elected Lex Luthor President of the US. /end sarcasm
Actually, you can't blame the populace of the DCU electing Lex Luthor, President of the United States. Like Corp said, Lex was not a convicted felon and he actually made the effort to cover his **** up. And beforehand, he turned himself into the police and found innocent by a court of law, with the public believing him. And he was beloved by the people of Metropolis because they saw him as the source of jobs, charity, and prosperity for the city.
Then you have Luthor's popularity being boosted by the events of No Man's Land where he violated US law and went into Gotham and committed the resources of LexCorp to rebuild Gotham City and helping her people. The government couldn't stop Luthor on account that No Man's Land was very unpopular within the American public, let alone imagine how bad it would look that the government was stopping Luthor from helping people, it would have taken a military action to remove Luthor out of Gotham, and Luthor had too many Congressmen in his pocket to get Congress to act against him.
And then his popularity skyrocketed after he successfully coordinated the US military, Earth's superheroes, and various alien powers like Apokolips to stop Imperiex and Brainiac 13 from destroying the universe.
So yeah, at least there were legitimate reasons for the populace of the DC Universe for loving Luthor. Norman Osborn on the other hand, was already outed as the psychotic Green Goblin when he was appointed Director of H.A.M.M.E.R.