There are several reason listed in this thread why popular vote is bad (Germany Nazi-Jews ex., top cities rule the rest of the county another, the list of these cities won't change much, etc.)
Every system has flaws, popular vote has more than electoral college. Just because the last election was flawed (won't argue that, lets just assume) doesn't mean the system needs to be ditched. It just shows the system isn't perfect, well, nothing is.
Most Americans don't ultimately care whether their presidential candidate wins or loses in their state or district . . . they care whether he/she wins the White House. Voters want to know, that even if they were on the losing side, their vote actually was equally counted and mattered to their candidate. Most Americans think it is wrong that the candidate with the most popular votes can lose. We don't allow this in any other election in our representative republic.
Adolf Hitler did not come to power in Germany as a result of a national popular vote.
The biggest cities are almost exactly balanced out by rural areas in terms of population and partisan composition.
16% of the U.S. population lives outside the nation's Metropolitan Statistical Areas. Rural America has voted 60% Republican. None of the 10 most rural states matter now.
The population of the top five cities (New York, Los Angeles, Chicago, Houston and Philadelphia) is only 6% of the population of the United States and the population of the top 50 cities (going as far down as Arlington, TX) is only 15% of the population of the United States. 16% of the U.S. population lives in the top 100 cities. They voted 63% Democratic in 2004.
Suburbs divide almost exactly equally between Republicans and Democrats.
With the end of the primaries, without the National Popular Vote bill in effect, the political relevance of three-quarters of all Americans is now finished for the presidential election.
Because of state-by-state winner-take-all laws, not mentioned, much less endorsed, in the Constitution. . .
In the 2012 general election campaign
38 states (including 24 of the 27 smallest states) had no campaign events, and minuscule or no spending for TV ads.
More than 99% of presidential campaign attention (ad spending and visits) was invested on voters in just the only ten competitive states..
Two-thirds (176 of 253) of the general-election campaign events, and a similar fraction of campaign expenditures, were in just four states (Ohio, Florida, Virginia, and Iowa).
Issues of importance to non-battleground states are of so little interest to presidential candidates that they don’t even bother to poll them individually.
Over 87% of both Romney and Obama campaign offices were in just the then 12 swing states. The few campaign offices in the 38 remaining states were for fund-raising, volunteer phone calls, and arranging travel to battleground states.
Since World War II, a shift of a few thousand votes in one or two states would have elected the second-place candidate in 4 of the 15 presidential elections
Policies important to the citizens of non-battleground states are not as highly prioritized as policies important to ‘battleground’ states when it comes to governing.
“Battleground” states receive 7% more federal grants than “spectator” states, twice as many presidential disaster declarations, more Superfund enforcement exemptions, and more No Child Left Behind law exemptions.
Compare the response to hurricane Katrina (in Louisiana, a "safe" state) to the federal response to hurricanes in Florida (a "swing" state) under Presidents of both parties. President Obama took more interest in the BP oil spill, once it reached Florida's shores, after it had first reached Louisiana. Some pandering policy examples include ethanol subsidies, steel tariffs, and Medicare Part D. Policies not given priority, include those most important to non-battleground states - like water issues in the west.