Trump surges, as Cruz banks on Indiana roadblock

With Donald Trump on an increasingly credible path to victory, his chief rival in the Republican presidential nomination race, Ted Cruz, fought back Friday in Indiana, the next primary battleground.

Once seen as inconceivable, Trump's quest for the 1,237 delegates needed to win the nomination outright is no longer mission impossible.

Winner-take-all Indiana hosts its contest on May 3, and it will be key for the bombastic billionaire as well as for Cruz, setting up a dramatic showdown that could decide once and for all whether Trump is stoppable.

With the Hoosier State suddenly under a political microscope, Republican Governor Mike Pence took to a local radio station Friday to offer a lukewarm endorsement.

"I'm not against anyone, but I will be voting for Ted Cruz," Pence said.

The governor, however, commended Trump for rallying grassroots voters, and said he would "work my heart out" for "whoever" becomes the Republican standardbearer and faces likely Democratic nominee Hillary Clinton.

Trump beamed with confidence as he hosted Indiana rallies with retired college basketball coach Bobby Knight, a local legend.

"If we win Indiana, it's over," Trump proclaimed in Evansville Thursday.

Cruz, appearing in Indiana alongside his newly announced vice presidential pick Carly Fiorina, said Friday he was confident that "Midwestern common sense" would prevail and the state would tilt his way.

After Trump crushed his opposition by sweeping all five states that held primaries Tuesday, the nomination landscape suddenly favors the billionaire.

California, which votes June 7 on the last day of Republican primaries, is crucial for both Trump and the anti-Trump movement.

That the largest state is even a factor in the race is evidence of how the GOP battle is going down to the wire, and tensions boiled over Thursday at a Trump rally in Costa Mesa.

Protests at the event turned violent, as hundreds of demonstrators clashed with police outside the Orange County amphitheater, hurling rocks and smashing a police car window. Police reported some 20 arrests.

The debate over Trump was now focused on whether he can win a majority of the 2,472 Republican delegates who choose the nominee at the party's convention in July.

Should he reach the magic number of 1,237, the nomination is his because delegates secured in statewide races are bound to vote for their candidate in the first round.

Cruz, a conservative Texas senator, however, has run circles around Trump in wooing convention delegates in the event there is no first round winner.

If Trump falls short of a first round win, Cruz hopes to snatch the nomination on a second ballot when most delegates become free to vote for whomever they choose.

Former candidate Jeb Bush, who has endorsed Cruz, acknowledged Trump is "close" to reaching the threshold.

But "if he doesn't get to 50 percent he might have problems garnering the delegates" at the convention, Bush told CNN.

But Trump remained bullish: "I think we get that 1,237."

- Unbound delegates key -

Trump currently stands at 991 delegates, with 10 of the 50 US states yet to vote.

Of the remaining 502 delegates up for grabs, Trump needs 49 percent. If he maintains the same level of voter support in the remaining contests he has had in recent weeks, victory is assured.

"I think he can likely get to 1,237," Christine Barbour of Indiana University at Bloomington said of Trump, adding "I'd say they (Cruz and Kasich) are in for the duration and we won't know anything until California."

A New York Times projection says Trump will probably secure as many as 1,289 delegates, including 154 of California's huge trove of 172.

But there is a scenario in which Trump no longer even needs Indiana.

More than 100 Republican delegates are headed to the convention unbound; they can vote for any eligible candidate they choose.

Among them are 54 delegates from Pennsylvania, which voted Tuesday. Trump won it handily, securing the 17 bound delegates.

But he also snatched 41 of the 54 who are free to vote their preference, according to ABC News.

Calvin Tucker, an uncommitted delegate elected from Pennsylvania's 2nd District, said if Trump were close to 1,237, it would be hard to oppose him.

"If he's 1,236, absolutely," Tucker told AFP. "If my vote is the deciding vote, yes, I'm on board."