His adultery while being married speaks loudly concerning his morality. His morality is an indicator of what kind of president he would make.
Billy Jeff was an immoral president and he started the decline this country has been on since.
I was one of the first to call Rubio out on his Gang of Eight maneuver, but I suspect this Rubio thing is just a smear. Trump, though, is a serial adulterer, with an entire Vanity Fair article devoted to his adulterous dalliance (followed by marriage) with Marla Maples back in 1990. Clinton was also an adulterer, but he was probably one of the best Democratic presidents we've had in the past century, from a policy standpoint. He was the one Dem who actually pushed the country in a conservative direction. He could have vetoed welfare reform, but did not. He could have vetoed tax cuts, but did not. I think when conservatives look at him decades from now, they'll see him as one of the least bad Dems, and Obama as the worst.