last inning

Meaning 1
From baseball: There are 9 innings in a game, unless the game is tied, when it goes into overtime until the tie is broken.
Sentence 1
It's the last inning and the Phillies are up to bat against the Braves. The game is tied 3 to 3. It may go into overtime unless the Phillies or the Braves get a run in the 9th.
Meaning 2
"The game" of an election, is almost over; the last inning of an election could be the last few weeks before voters vote.
Sentence 2
Let's get this act together. It's the last inning: we are down 3% and need to win those 5 Senators to take control.