The final poll numbers for 2012 aren't in yet, particularly in the west coast states where Obama's lead may still go up, but whether you are counting the percentage of the vote, the electoral vote count, or even the number of votes short the candidate was of actually winning, John Kerry was a better candidate in 2004 than Mitt Romney was in 2012.
Vote Count
According to Dave Leip's Atlas, the count currently stands at:
Obama: 62,616,535 (50.61%)
Romney: 59,090,075 (47.76%)
Other: 2,019,496 (1.63%)
And in 2004, courtesy of President Elect:
Bush: 62,040,610 (50.7%)
Kerry: 59,028,444 (48.3%)
Other: 1,226,291 (1.0%)
So these numbers tell us a few things:
Romney got a smaller percentage of the vote than Kerry did.
The total vote count for Romney is currently less than 100,000 votes above Kerry, but his percentage is already lower (47.76% to Kerry's 48.3%). This may fluctuate a bit, but it looks pretty certain that he will not be able to do better than Kerry's number. I guess that goes to show that the anti-Bush forces in 2004 were stronger and larger than the anti-Obama forces were.
Also of note, Obama has more votes at this point than Bush did in 2004. So the pro-Obama forces were also stronger in 2012 than the pro-Bush forces were in 2004.
Kerry got more electoral votes than Romney did.
Romney is on track to get a mere 206 electoral votes. Kerry's states added up to 252, although one of his electors voted for John Edwards for President, so he only actually got 251. Nonetheless, 251 > 206. Romney would have had to win Florida, Virginia, AND New Hampshire to tie that 252 number.
Kerry was closer to flipping the election his way.
While Kerry clearly lost the popular vote by a couple million votes, he only had to take Ohio to have won the electoral college (which would have been nice, but I definitely wish the vote was a popular one). If you look at Ohio, Kerry lost the state by a mere 118,601 votes, meaning a switch of 59,301 people would have given him the presidency. I actually forgot it was that close, and remember the heartbreak that year of realizing we had four more years of Bush ahead of us.
Contrast this to Romney. Per Nate Silver, the states closest to flipping to Romney were (in order): Florida, Ohio, Virginia, and Colorado. These states would have given him 275 votes, and would have been the easiest to flip.
But how easy? Again, according to Dave Leip, Romney lost each state by the following amount of votes:
Florida: 73,858
Ohio: 107,259
Virginia: 143,360
Colorado: 117,276
So he needed (respectively):
FL: +36,930
OH: +53,630
VA: +71,681
CO: +58,639
For a total of 220,880 votes spread out over 4 states. Clearly a much weaker position than Kerry was in. Too bad ORCA couldn't tell him where to send those last minute robocalls huh?
In Conclusion...
The Republicans have every right to feel bad about Romney's performance. Since 2004 it has become the common belief that Kerry fielded an incredibly weak campaign, yet the numbers show that he was less than 60,000 Ohio votes away from winning the election. In all objective ways of looking at it, Romney fared even worse. He doesn't even have 100,000 votes more than Kerry got, yet he paid multiple times more for them than Kerry did. His percentages are below Kerry's across the board though, and considering how he's already implying that he was cheated out of his victory by the takers in this country, I hope he realizes how badly he did. His candidacy doesn't just deserve to be considered one of the worst in modern history - it deserves to be pitied and spoken of in derision only.