It's a different system for sure but its the same for every Presidential contender, same rules for everyone. Lets have a look at the last 10 POTUS's and see if the results inheritantly favour a particular party.
https://www.quora.com/Who-were-the-last-10-American-presidentsDonald Trump (2017-)....................................Republican
Barack Obama (2009–2017)..........................Democrat
George W. Bush (2001–2009).......................Republican
Bill Clinton (1993–2001)....................................Democrat
George H.W. Bush (1989–1993)........................Republican
Ronald Reagan (1981–1989)............................This guy swung both ways
Jimmy Carter (1977–1981)................................ Democrat
Gerald Ford (Aug 9 1974–1977)........................Republican
Richard Nixon (1969-Aug 9 1974)......................Republican
Lyndon Johnson (Nov 22 1963–1969)...............Democrat
John Kennedy (1961-Nov 22 1963) .....................Republican
Thats a pretty even result, it virtually goes Dem then Rep then Dem then Rep.... Democrats can win if the people believe in them and their policies.
Don't forget we've just had to put up with Obama for 8 yrs so it's our turn now, you guys may be sitting it out until '24 to keep the balance flowing.