Here is a plan for Bush to supercharge the Conservative base: 1) As you suggested, borders. 2) Language - challenge Congress to pass a Bill making English the official language of the USA and driving an initiative to save on costs by removing multilingualism in all areas accept those dealing with tourists and those seeking legal immigration. No more multilingual courts, common forms, and other areas where in any other country, it would be in their own language. 3) Culture - reaffirm opposition to Gay marriage and officially reaffirm the Judeo-Christian principles upon which the USA was founded. 4) Immediately create 3 lists of countries - enemies, friends and cowards. Stop MFN status to all enemies, reduce it for cowards and reward only friends. The criteria for the enemies list would include aid to rogue nations and terrorists, excessive espionage against us, and active preparation for war. #1 on the enemies list = the PRC.
Doing these things would energize the Conservative base - it would be like what happened in 1980 and 1984.