According to the campaign, the tweet from Romney's official account was responding to a video shown earlier in the day at the Democratic convention.
"Government is the only thing that we all belong to. We have different churches, different clubs, but we're together as a part of our city or our county or our state," the narrator said in a video shown on the convention floor. Buzzfeed has the portion of the video.
The video seems to echo the point President Obama was making in a campaign speech in Virginia earlier this summer, a speech that has become contentious after the GOP turned their response into a major theme of the Republican National Convention last week.
"If you were successful, somebody along the line gave you some help," Obama said in the July speech. "There was a great teacher somewhere in your life. Somebody helped to create this unbelievable American system that we have that allowed you to thrive. Somebody invested in roads and bridges. If you’ve got a business — you didn’t build that. Somebody else made that happen. ... The point is, is that when we succeed, we succeed because of our individual initiative, but also because we do things together. There are some things, just like fighting fires, we don’t do on our own."
Republicans have blasted Obama for the "you didn't build that" line, but Obama's campaign has fired back the outrage requires taking the president out of context. Romney has said Obama was demonstrating he prioritizes "the collective" over the individual.
"The point he was trying to make was things like education, infrastructure ... are things we do together," White House senior adviser David Plouffe noted last Sunday.
The chant "We built it" proved very popular with the GOP crowd last week in Tampa, Fla.