Donald Trump enters Illinois’ March 15 primary as the clear front-runner for the GOP nomination for president.

He’s dominated most of the primaries and caucuses to date, and he has significant leads over his rivals in national polling.

While he’s in a strong position, Trump, a billionaire real estate tycoon and reality TV star, still is no guarantee to secure the nomination.

Because of the number of candidates in the field, it’s possible none of the Republican presidential hopefuls will have won the required number of delegates to secure the nomination entering the July 18 start of the GOP convention in Cleveland.

Because Trump is such a polarizing candidate, that could lead to a brokered convention in which delegates are able to change their votes to a different candidate after the first ballot.

Needless to say, this is a vital election year for the country. That’s why Illinois voters should press the reset button on the Republican nomination process.

Trump’s candidacy is rooted in negativity and preys on the understandable anger of frustrated voters. We understand why voters would welcome a candidate from outside traditional political channels, but Trump is not the answer. He is that angry email you want to send but really shouldn’t. He is that nasty phone message you want to leave but always will regret.

Trump is a bully who’s more apt to name-call and belittle than to discuss policy in any detail. He offers little in the way of substance or leadership. His plan to build a 1,000-mile-long wall along the Mexican border that’s at least 30 feet tall to keep illegal immigrants out of the U.S., and also to have Mexico pay for it – his most specific policy message, by the way – is, well, laughable.

And let’s face it. Trump isn’t a true Republican. He’s supported liberals and liberal causes throughout his career.

U.S. Sen. Ted Cruz of Texas also is not the answer. Like Trump, Cruz is a divider, not a uniter. A far-right-wing conservative, Cruz cannot attract the independent voters needed to win a general election against the Democratic nominee. He is beholden to big oil and among the staunchest deniers of the science of climate change.

U.S. Sen. Marco Rubio has the best chance to unite the party and lead it in a new direction. He was elected to the Senate as a tea party candidate but also has worked closely with members of the Republican establishment.

The son of Cuban immigrants, Rubio can expand the party’s base among Latinos.

Rubio is a policy wonk who focuses on solutions rather than problems. He delivers an uplifting message about America’s potential and is an advocate for smaller government – he would reduce all federal spending to 2008 levels except for defense. He supports overhauling what he calls America’s outdated educational system, including increasing vocational training. He supports some sort of legal status for undocumented workers, but only after U.S. borders are secure. He wants to reform the federal tax code and cap economic regulations.

Ohio Gov. John Kasich also remains in the race.

We endorse Rubio for the Republican nomination for U.S. president.