Paul Ryan also campaigning for Congress
He skipped every forum for candidates for statewide office and sent surrogates to read prepared statements.
It didn't hurt him a bit: Biden won with almost 65 percent of the vote - his largest win margin in seven races.
He never served a day of the term, resigning to assume the vice presidency.
In 2000, Democratic Sen. Joe Lieberman easily won a new Senate term while he was the running mate of unsuccessful presidential nominee Al Gore.
Back in Wisconsin, Ryan campaign manager Kevin Seifert said his team knew Romney could tap the congressman when they developed their game plan. Ryan spent his summer as he normally does, hitting local parades and holding town halls.
"Voters know Paul very well. That's not going to change in the fall because he hasn't been here," Seifert said.
Bumper stickers and stacks of signature green "Ryan for Congress" are ready for distribution.
At his campaign headquarters last week, a handful of workers carried on last week with typical campaign tasks.
During a brief Wisconsin homecoming, Ryan met privately with a few dozen family and staff members to thank them for their efforts and to urge them on.
In the days before Romney made his choice public, Ryan crammed in ad shoots at various spots around town featuring supporters and testing out lines he would use in his debut remarks as a vice presidential candidate. Supporter Cheryl Gray, a former furniture store owner who appears in some scenes, grew suspicious when a Sunday shoot was suddenly canceled.
That was when Ryan secretly traveled east to meet with Romney and his vetting team. The filming resumed Monday and Tuesday and when Gray asked Ryan if he'd be joining Romney on a swing state bus tour, she said he played coy.
"He was kind of taken aback," Gray said. "He really did not let on."
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