First, you have control the media. Media will help you cover bad news, distract public attentions, divide your opponents and brainwash voters.
1. You keep your base with you by appealing to your base and not alienating them. Let's face it; Romney and GOPe tried to go to the center and lost because they alienated the conservative base.
2. If you want to keep your base, you back your people running in the elections or who are already in office. Biden is defended constantly though he is an absolute idiot, but because they do the base keeps energized. Akin and Mourdock made gaffs to be sure, but because Romney and everyone running his election came out on the side of the Democrats and told them they should step down and not run, the conservative base was angered and stayed home.
The underlying premise; always run someone who can rally the base and let the other segments of voters, the moderates and liberals, decide for themselves who they will back and don't worry about trying to "appeal" to them or go to the center. In addition, you back and protect your own, no matter how goofy they are or if you don't totally agree with their stances on issues.
Reagan ran on conservative ideas and won, Bush Sr got one term before he was crucified on a broken promise because appealed to the conservative base. So did Bush Jr. But Dole, McCain and now Romney tried to run to the center and lost.