CARACAS, Venezuela (Reuters) - Venezuela's leftist President Hugo Chavez on Sunday promised hundreds of thousands of supporters he would win a resounding victory in his December 3 reelection bid he describes as a challenge to Washington. The former soldier and self-styled revolutionary is favored in the polls to beat rival Manuel Rosales after building a solid political base through a social development campaign financed by oil revenues. Chavez supporters flooded Caracas thoroughfares waving flags and banners, congregating in different parts of the downtown a day after Rosales sympathizers held a similar march to close his campaign in the capital city....