Candidate Obama had these words to say when running for the office of President of the United States of America.
If you think that President Obama has done a good job and should be re-elected, do nothing.
If you think that President Obama has not done a good job and should be replaced, then you should get off your behind (and away from the keyboard) and get involved in replacing him.
If you have a favorite candidate for President in the Republican party, you should donate money and time to help that campaign win the nomination. If your candidate does not win the nomination, you can either join the winning campaign or (if your ego prevents that) get involved with the local Republican party efforts to Get Out The Votes during the early election period and on election day.