Fair political polling is a statistical balancing act
Poll: Trump holds small lead over Cruz in Indiana
A WTHR-HPI survey released Friday found Trump taking 37 percent support, followed by Cruz, at 31 percent, and John Kasich, at 22 percent.
It's the only public poll of the state released so far this cycle.
The pollsters will release a detailed breakdown of the data later this evening but said the race becomes "a virtual tie" between Trump and Cruz "when you drill down into the numbers into core Republicans."
Indiana will be an important test for Trump in his quest for the 1,237 delegates he needs to win the nomination outright and avoid a contested convention.
The GOP front-runner is expected to build on his delegates lead in a string of contests along the East Coast on April 26.
If he can continue that momentum into Indiana on May 3, he'll be in good position to close the deal heading into the final stretch or the primary.
But many political watchers believe Indiana's conservative electorate will ultimately boost Cruz to victory in the Hoosier State.
Kasich trails but is making a late run at the state, opening two campaign offices there this week and spending election night there this Tuesday.
Some Republicans are worried that Kasich's efforts will suck support away from Cruz and end up benefitting Trump.
There are 57 delegates up for grabs in Indiana, with 30 awarded to the statewide winner and the remaining 27 allocated in winner-take-all contests at the Congressional district level.
The WTHR-HPI poll of 500 likely voters was conducted between April 18 and April 21 and has a 4 percentage point margin of error.