INDIANAPOLIS — For the second time in the three most recent presidential primary elections, Indiana voters could have a decisive say in which candidates win their party's nomination.

On May 3, Hoosier Republicans will choose whether to help front-runner Donald Trump get closer to a first-ballot nomination at the Republican National Convention.

Or, they can try to stop Trump by supporting U.S. Sen. Ted Cruz, R-Texas, Ohio Gov. John Kasich, or any of the six other GOP candidates who quit the race long ago but whose names still will appear on the ballot.

The WTHR/HPI Indiana Poll released last week shows 37 percent plan to vote for Trump, 31 percent for Cruz and 22 percent for Kasich.

Indiana Democrats going to the polls next Tuesday can put the race almost entirely out-of-reach for Vermont Sen. Bernie Sanders, making former Secretary of State Hillary Clinton the presumptive nominee.

That would be a reversal of 2008 when Clinton narrowly won Indiana's Democratic primary, but Barack Obama added enough Hoosier delegates to his lead to effectively deny Clinton a realistic path to the nomination.

The poll shows Clinton with a 48 to 45 percent lead over Sanders, but that's within the 4 percent margin of error for the April 18-21 survey of 500 likely Hoosier voters.

This year's presidential candidates, especially on the Republican side, already are airing television ads, have visited Indiana or will be here this week following primaries Tuesday in five northeastern states.

Between Tuesday and May 3 there are no other elections, making Indiana the center of the nation's political universe for at least seven days.

"That hasn't happened too often in my lifetime, and frankly I think it's going to be great for Hoosiers and it's going to be even better for these candidates because Hoosiers are people with strong hearts and strong opinions," said Republican Gov. Mike Pence.

"I expect it's going to make every one of these candidates better for having to come to compete in Indiana for votes."

Prior to the 2008 Democratic contest, Indiana last mattered in a presidential primary in 1976 when former California Gov. Ronald Reagan won a narrow victory in the Republican primary over President Gerald Ford.

Reagan carried his Indiana momentum to the GOP convention where he nearly managed to wrest the nomination from the incumbent president for the first time since 1884, and what would have been the sixth time in U.S. history.

Nevertheless, some Hoosiers believe Indiana could have a more regular impact on the presidential nominating process if the state's primary were held earlier in the year when more candidates still are in contention.

Often both parties' presumptive nominees are decided well before Hoosiers vote on the first Tuesday after the first Monday in May.

While Democratic and Republican party rules privilege Iowa and New Hampshire as the first caucus and primary states, nothing prevents Indiana from selecting its preferred presidential candidates shortly after those states vote.

House Speaker Brian Bosma, R-Indianapolis, is among those who think "it would be wonderful" to move Indiana's primary up.

"The problem is if you move all primaries up, then you've got every office — Congress, legislative offices, statewide offices — all with a very early primary, and then there's eight months until the the general election," Bosma said.

In addition, the General Assembly meets until mid-March in even-numbered years. So if Indiana has its primary the same day as Illinois, March 15 this year, Hoosier lawmakers would have to do their jobs while simultaneously running to keep their jobs.

Bosma said one option is to leave Indiana's primary election in May, but have the state's political parties run early presidential-only caucuses.

Under that system, citizens gather at local meetings to select their presidential picks, and ultimately the delegates to each party's national convention, without forcing counties to shoulder the costs of a full-blown election.

Bosma hinted the Legislature may look next year at creating a presidential caucus, or at least sometime before the 2020 campaigns begin.

It's a familiar idea.

In 2009, former state Sen. Sue Landske, R-Cedar Lake, who died last year, proposed a two-year study of how best to ensure "every Indiana citizen (has) the same opportunity as citizens of other states when nominating presidential candidates."

The 12-member committee set to be created by her Senate Concurrent Resolution 28 would have reviewed presidential primary practices in every state, including their cost, as well as evaluated the possibility of Indiana holding its primary the same day as other Midwest states to create a Super Tuesday-like regional election.

Landske's plan was approved by the Republican-controlled Senate, but did not advance in the Democratic-controlled House.