I believe Donald is a little bit of both.
If he weren't running for president it's doubtful many folks would even being paying attention to politics this early in an election cycle.
People who admire him like the fact that he is free of lobbyist pressure because he doesn't need their money.
He's also not "politically correct" and never apologizes.
Trump also promises to "Make America Great Again" which brings back memories of the industrial revolution when America was thriving. He also feeds into the base's belief that any hardship we're experiencing is due to illegal immigration and bad trade deals.
Trump promises to solve both issues!
Republicans who dislike him see him as saying anything to get elected. Many traditional established or moderate Republicans don't consider him to be a "true conservative".
He's in favor of a single payer insurance system which goes way beyond what Obamacare is. He's been pro-choice in the past, and he has likely alienated the Latino voting block which is needed to win a general election.
Building a 1900 mile wall and deporting 11 million people from the U.S. is not practical and borders on insanity in their eyes.
The Republican National Committee is attempting to stop Trump!
Democrats believe Trump is a Godsend!
They feel Donald exposes Republicans to be heartless greedy racists. They also feel he lacks foreign diplomacy skills. They hope he wins the nomination and can't wait for the general election debates.
The real suspense here is will the RNC (allow it's voters to choose) their party nominee or do they have plans to sabotage Trump if he starts winning early primary states?
If the heads of his own party are against him it's unlikely he will win the nomination let alone the presidency. It will be interesting to see!