help! what does the phrase "got the bandwagon rolling" mean?

i am doing translation and i find it, especially the words in red, really hard to understand, help me! orz...


here is the original text:


Hlinko, Kofinis and Margulies had the insight to see the post-Sept. 11 wisdom of the Democratic Party nominating the kind of Democrat that no Republican consultant had experience running against, a four-star general.

They got the bandwagon rolling with a Web site, energetic self-promotion, and an ultra-low budget TV ad campaign.