Democrats stand on the verge of a major legislative victory in the Congress on this Sunday, as they make one final push to get a pair of health care reform bills through the U.S. House.

"It's in your hands," President Obama told Democrats at the U.S. Capitol during a Saturday visit, acknowledging that this would be a "tough vote" for many lawmakers.

"Don't do it for the Democratic Party," Mr. Obama said, "Do it for the American people."

To ensure that victory, Democrats will be checking often on each other, to make sure that no vote gets away.

One of those tasked with asking members where they stand is Rep. Hank Johnson (D-GA), who was buttonholing colleagues off the House floor on Saturday - just to be sure.

"There's no telling what has happened to a particular Congressperson between then and the next time I see them," Johnson told me.

"They can change from 'Yea' to 'Nay' overnight or in a couple of hours," Johnson said.

And with almost no margin for error, letting just one or two votes get away could be catastrophic for Democratic leaders.

It was hard to get a fix on the true ranks of the undecided late on Saturday night, as some like Rep. Jim Cooper (D-TN) stubbornly kept his options open.

"He is reading the bill," said Cooper's Press Secretary Peter Boogaard.

A Blue Dog Democrat, Cooper voted 'Yes' in November, and is certainly a key vote this time around as well.

"I still think the Speaker's short on votes, but she is getting close," said Rep. Steve Austria (R-OH), one of many Republicans hoping that somehow a wrench gets thrown into the plans of Democrats.

"It's very close right now."

So close, that Rep. Tom Price (R-GA) was calling doctors and medical professionals around the country, urging them to weigh in with their lawmakers as well.

Price had his phone almost glued to his head on Friday just off the House floor, barely breaking to run back in for votes.

"He's a no vote," Price was overheard to say about one Congressional Democrat.  "At least he says he's a no vote."

When asked about his efforts, Price laughed and admitted that he had been on the phone so much, his cell phone battery died.

We'll see today if Republican efforts to stop Democratic health reform plans run out of juice as well.