The left was not voting for Kerry, they were voting against Bush. Bush isn't running next time. Cheney won't be running. Hard to push against "Bush and Cheney" when neither is in the race. Some of Kerry's voter base included conflicting demographics for example homosexuals vs. Christian or even muslim black voters; they oppose same sex marriage AND they oppose attempts to liken the homosexual campaign to racial segregation (Kerry had to FLIP FLOP).
Bush got votes from "911 Democrats" who switched parties on the WOT issue (Dick Morris, Ed Koch, Ron Silver, et al), Christian conservatives who focus on abortion and same sex marriage (the Amish voters factor into Bush's Ohio victory to some degree), Americans against Kerry (a known traitor to his nation during Vietnam and someone who indicated he would sell us out to the United Nations), Americans against the Mainstream Media (the backlash to their support of Michael Moore, Rock The Liberal Vote, constant Bush bashing, hoaxes as news such as Rathergate...), and those who actively support President Bush in all of his policies (or at least see that he offers a better shot at the policies they want than Kerry could ever offer).
George W. Bush succeeded in getting more popular votes than all "ANYBODY BUT BUSH" candidates combined. A healthy majority of 3million voters. Bush got more votes than Ronald Reagan. Voters wanted to make sure that Kerry did not get in office.
Will people turn out next time? Who knows? Totally depends on what happens over the next 4 years. Will the UN disintegrate after being exposed as a part of the problem? Will the right to LIFE be clarified in the Constitution so that abortion is off the table as an issue? Will same sex marriage be off the table?
Will war or national security have new conflicts to worry voters?
The left is selling socialism a little at a time. Expect to see them yet again selling nationalized health care, more environmentalism (get people out of cars), still opposing school choice. Welfare and Social Security may also be yet again a part of their drumbeat.
I do not see this happening. It will take grassroots organization at the grass roots level to hold their feet to the fire.
WE need to get before the voter what the long term issues are and force the issue.