If President Obama loses his bid for a second term next year what direction will the Democratic Party take politically? I mean since Obama and his supporters are from the liberal/left wing of the party
Stop there. Obama's biggest detractors within the Democratic party are from the left wing of the party.
If anything, Obama being defeated will lead Democrats to become more aggressive, disciplined, and liberal (though to a lesser extent than the Republicans have in the past few years, since there are far more moderates in the Democratic party than in the Republican party).
Going further to the left and becoming more ideological isn't going to solve things for the Democrats. Especially if they have any aspirations of taking back the Senate or making gains elsewhere in this scenario, since many of the states the Dems picked up/defended seats in during the 2008 election were deeply Blue or light Blue Atlas color states. If the Dems moved further left they are going to turn the table in the favor of the Republicans for instance in the case of the Senate, since incumbents in places like North Carolina, Louisiana, Arkansas etc will be left vulnerable to Republican challenges.
Additionally, such moves would scare off centrist voters, suburbanites, Reagan Democrats, and pro-business voters.
So in short a left-wing version of the Tea Party would do more harm to the Democrats then good at least in the short term.
The Dems would be much better off moving towards more centrist/populist platforms and themes like those seen during the Clinton years.