POWER RANKINGS: Here's who has the best chance at being our next president
There are signals on both sides that the race could drag on until the final primary day of June 7, when California votes. And for Republicans, at least, the fight could go to the convention floor in July.
Five candidates officially remain in the race - though only two have mathematically realistic chances of claiming their parties' respective nominations before their conventions.
Two of the three remaining GOP candidates - Sen. Ted Cruz Texas and Gov. John Kasich of Ohio - have mathematically impossible odds of obtaining enough delegates before the convention.
On the Democratic side, Sen. Bernie Sanders needs a seemingly improbable turn of events, given Democratic primary rules that give more of an edge to the frontrunner at this point.
Nevertheless, they are all powering on, looking to stop frontrunners Donald Trump and Hillary Clinton.
With all that in mind, we take another look at who has the best chance of making it to the White House to succeed President Barack Obama.
Our rankings are based on the Real Clear Politics averages of national polls and those in states voting in upcoming contests (Pennsylvania, Maryland, Connecticut, and Indiana). We also factored in the candidates' delegate counts and their relative paths to the nomination, as well as their momentum (or lack thereof) over the past few weeks.
Here's a look at where all the candidates stand.
All poll results as of Monday.