Actually, at least in the USA's current configuration, the electoral college appears to favor Democrats. A tie or small Romney win in the national popular vote, for instance, would have more likely than not equated to an Obama win.
I think it's genuinely about ideology, here: favoring the will of the people over the historically contingent existence of the electoral college is making a kind of ideological statement. The kind that appeals to many liberals and is a turn-off to conservatives.
The electoral college has several distortions. The big one and it's raison d'etre is that it distributes power towards rural states and away from population centers. There's little question which party that favors.
Now it's certainly possible that Romney could have won the popular vote and lost the electoral college due to the first past the post distortion that dilutes big majorities. But that really says more about the relative competence of the two campaigns then it does about whether the electoral college structurally favors the Democrats. Romney clearly needed to run quite a bit farther to the middle than he did.
One way to evaluate claims like these is by looking at an extreme comparison:
Alternate World 1: red states are split into mini-versions of themselves the size of a single CD, a more than doubling of their electoral value. Ignoring effects on the Senate of course, this is just a test of POTUS electoral procedure.
Alternate World 2: 25 very red and 25 very blue states of combined identical population are subject to the whims of a single swing district that is right in the middle of the spectrum.
It should be obvious that the sorts of presidents you get in world 2 look a lot more like those in popular vote world than the ones you'd get in world 1. Actually we might expect that the liberal candidates in world 1 are nearly to the right of the conservative candidates in world 2.
Do you remember the year 2000 at all?
It comes down to the fact that anti-Obama voters were wasted in very red states that Romney had zero chance of losing, while Obama's popular support was better distributed among both blue and swing states.