Big numbers and high stakes are riding on the ballot in November: 435 House seats, 35 Senate seats, 39 governorships − and the country's course for the final two years of President Donald Trump's term.
Who will win?
In the math of the midterms, a handful of statistics can signal the odds of a squeaker or a tsunami, of a Democratic sweep or the resilience of the Republican status quo.
"If we lose the midterms, you'll lose so many of the things that we're talking about, so many of the assets that we're talking about, so many of the tax cuts that we're talking about, and it would lead to very bad things," Trump told supporters at a rally in Iowa that kicked off his election-year campaigning. "We have got to win the midterms."
Contrast the president's warning with the confidence of House Democratic leader Hakeem Jeffries of New York.
