Barack Obama spent the last couple of days fending off the firestorm over James Johnson. Now Obama is getting flak for hiring mainstream advisor (“Wall Street economist,” in liberal-speak) Jason Furman to provide economic expertise. The left wing crowd is upset because they were under the impression Obama was a protectionist, pro-labor, populist. Where did they get that impression? Probably from listening to Obama on the campaign trail. Now he talks up his love of free trade and affection for markets. So you can understand that the ultra-liberal base, which stuck with him throughout the primaries, might be peeved.

This highlights the problem Obama faces as he flips and flops his way to the center on a variety of topics. If the Left is this upset about one economic advisor imagine the reaction if Obama moves substantially on the surge or acknowledges the Democrats were unduly pessimistic about our progress against Al Qaeda. Now this is certainly a problem of Obama’s own making as he determined to run left of Clinton to seize the nomination. (And perhaps it was inevitable given his ultra-liberal voting record.) It is the historical dilemma faced by many Democratic nominees from George McGovern to John Kerry who captured the nomination and then had to repackage themselves for a more moderate electorate in the general election.

The problem for Obama, however, may be more acute because he must reverse course without undermining his “we are above all that” New Politics. Other politicians get a wink and a nod when they shift positions as pundits simply pass it off as part of the “process” of getting elected. But when you are running against the “process” things get a bit dicier.

And despite what spin the media would like to add, John McCain really does not have this problem. He managed to win the Republican race without shifting positions, in fact defying conservatives, on a range of issues (e.g. global warming, torture, immigration). He has other problems, but this is not one of them.

Given all that, it will be interesting to see how adept the McCain camp is in using the Obama policy shifts to undermine Obama’s core appeal, namely that he is a different kind of politician.