I agree with Phil: 2004 was no realignment. While it may have appeared to be a landslide compared to 2000 (and given the Election Night expectations of many, including me, that Kerry would eke out a narrow win), Bush's victory margin of 2.46% was quite slight by historical standards, comparable to Carter's '76 win by 2.06% or Wilson's 1916 re-election by 3.12%. His 286 electoral vote was the third lowest for any winner over the past 100 years, only exceeding his 271 total in 2000 and Wilson's 277 in 1916. Nor was there any dramatic shift in voting whether measured by state, county or demographic group.
In fact, the last four presidential elections have showed remarkable stability. In none of them has any candidate won more than 11% or so of the other party's identifiers. (Larry Bartels has shown that the tendency for partisans to vote for presidential nominees of the other party has actually declined significantly in recent years). Over those four elections, 34 of the 50 states have voted only for nominees of one party; these include California, Texas, New York, Illinois and Pennsylvania -- five of the six largest states. (By comparison, between 1964 and 1976, only two states did so -- Arizona and Massachusetts).
Despite the occasional to-ing and fro-ing due to events, the balance of party ID hasn't changed much since the Reagan years, when the GOP made big gains among white Southerners. (Those gains in the South are the primary reason why the Republicans now controlled Congress).
Michael Lind's claim that the Democrats are no longer a national party based on the vote-by-county map typifies the argument I call, "one coyote, one vote." There is a legitimate point that the Democratic vote tends to be a little more concentrated by district and state than is GOP support. But typically for Lind, he takes a small point, and so inflates its significance, and argues it so dogmatically and absurdly, that you just want to smack him upside the head. (Republicans used the one-coyote, one-vote argument most frequently after the 2000 election, never admitting, that despite all those swaths of red, Gore actually got a half-million more votes).