Even the Republican candidates for president — and their respective billionaire donors — aren’t too impressed with the other Republican candidates. The only one who has been scared out of running is Mitt Romney — and even he appears on Fox News all the time, begging to be lured back into the race.

For the first time in decades, there isn’t anyone resembling a clear frontrunner in a GOP presidential primary. And while several candidates are raising millions of dollars, “Undecided” leads most of the likely candidates in the polls.

It’s not hard to see what’s so unimpressive about the Republican frontrunners.

What Scott Walker lacks in economic results, he makes up in deficits and divisiveness. Ted Cruz was most popular among primary voters when he led the party to record unpopularity. Jeb Bush hasn’t won an election since his brother became widely regarded as the worst president of the last century. Rand Paul may appeal to young white conservative males but he could drive women and seniors from the party in droves. Louisiana Republicans are eager for Bobby Jindal to run, so in his absence they might have some hope of fixing their budget and jobs crisis. Dr. Ben Carson and Carly Fiorina have never won an election and it’s not hard to see why. Rick Santorum resembles a Mike Huckabee “after” picture in looks and beliefs, and the two of them could cancel each other out in Iowa, then have little chance of winning anywhere else. And Chris Christie may avoid being indicted, but the only thing he’s led New Jersey to is being the state people are leaving faster than any other.

That leaves Marco Rubio.

Once regarded as “the GOP savior,” the junior senator bet his career on his belief that Republicans would be smart enough to take immigration reform off the table for the 2016 election. He lost that bet, but he’s still the favorite of his billionaire backers and other savvy Republicans and analysts who recognize that only Bush is running a campaign that might have some appeal beyond Fox and Friends. They prefer Rubio to Bush, recognizing that the younger Bush is least popular among the diehard fans of his brother George W. Bush, while most everyone else sees his last name as shorthand for “I’m with stupid, who wrecked our economy and lost two wars.”

“Marco Rubio is the Michael Jordan of American politics,” Rubio’s pollster Whit Ayers, who surprisingly is a big Rubio fan, recently said. “Anyone underestimates his ability at their peril….He’s substantive, he’s talented and I am very confident that once the voters get the chance to see the kind of candidate he is and the kind of vision he paints for the country that they will place him in the top tier.”

Rubio won’t have to be Jordan to win the GOP primary. He’ll have to be Barack Obama.

To usurp Jeb Bush, his former mentor, he’ll have to wrest control of the party from the establishment that help elect two Bushes. And he’ll have to beat the former twice-elected governor of Florida in the Florida primary, or at least deny Governor Bush a convincing victory. That would be an impressive and highly unlikely feat — on par with what the current president pulled off in 2008, when he edged out Hillary Clinton despite the Clinton family’s enormous political capital. Though Rubio pulled off a similar fear before, when he knocked out a sitting Republican governor in a GOP primary, it’s more likely he’ll play the role of spoiler for Bush this time.

Despite his once-sane views on immigration, his pleasant demeanor, and his optimism — “There’s nothing that’s right with America that can’t be made righter by what’s right with America,” he seems to say at the beginning of each speech — his policies are atrocious. Possibly even more atrocious than those of his Republican competitors.

Here are five reasons President Marco Rubio would be horrible for America.

1. A tax cut bigger than George W. Bush’s
Rubio has managed to pull off a miracle. He came up with a massive tax-cut plan that conservatives such as Larry Kudlow don’t like. At $4 trillion, it’s larger than the Bush tax cuts and more weighted to the rich by eliminating all taxes earned from investments. But Kudlow and company don’t like that it doesn’t slash rates enough. And it would actually raise taxes on many middle-class families. When W. proposed a massive giveaway that led to the first decade without any net job creation since the Great Depression, we had a surplus. Rubio is proposing this as we still have a deficit that could grow quickly as more Baby Boomers retire.

Dynastic concentration of wealth is at near-Gilded Age peaks and could undermine the stability of our economy. But Rubio’s plan — like nearly every Republican tax plan — is a plot to make the richest, who have never been richer, even richer, while justifying cuts to the ever-shrinking services we provide to working people.

2. He’s not a scientist
The first-term senator pioneered the talking point, “I’m not a scientist” when it comes to addressing climate change. Though he lives in a state that is already threatened by the effects of global warming, he refuses to accept scientific consensus that humans help cause it. “Our climate is always changing,” he says often and despite economists, generals and insurance companies warning that unchecked carbon pollution could wreck our economy, Rubio believes the real danger is doing anything about it.

Of course, this doesn’t separate him from his Republican competitors. The only major party nominee who will accept climate science — and fight to keep President Obama’s historic efforts to tackle it — will be the Democrat.

3. Goodbye Obamacare and Medicare
The president’s signature health reform has expanded coverage to at least 11 million Americans while predictions of health spending for the next 5 years are now $2.4 trillion lower than economists estimated before Obamacare became law. Rubio wants to erase that coverage and risk those savings by adopting a “plan” that would eliminate most of the help the ACA gives to working families. It would also change the ban on discriminating against pre-existing conditions into high-risk pools, an unserious policy that was included in the Obamacare ramp-up and failed.

Like fellow Obamacare hater Paul Ryan, he would turn Medicare into a premium-support system that resembles today’s Obamacare, leaving seniors with greater health needs to the whims of the insurance market. Rubio suffers from the same unwillingness to accept that Obamacare is working as all his fellow Republicans. But if he really believed that, why would he punish seniors by putting them on it?

4. Same-sex marriage
Marco Rubio is very mad at those in the LGBTQ community for trying to pursue their right to marry by using the courts. He doesn’t believe in a constitutional right to same-sex marriage and wants Florida to keep fighting to keep its ban.

“Sen. Rubio seems indifferent to why we have a Constitution and why we have courts, or else he wouldn’t be condemning the courts for upholding constitutional guarantees of equal protection and the freedom to marry,” Evan Wolfson, president of Freedom to Marry, said. “Over 60 courts now, state and federal, with judges appointed by Republican as well as Democratic governors and presidents alike, have found that discriminatory restrictions on the freedom to marry (some enacted by legislatures, some by ballot-measure attacks) violate our Constitution.”

Bans on interracial marriage were eventually ended by the Supreme Court. Does Rubio think we should have waited for all 50 states to have figured that one out?

5. The end of reproductive rights
Senator Rubio has been very clear that he would only nominate Supreme Court Justices who do not support Roe v. Wade‘s guarantee of reproductive rights based on “a right to privacy.” He cited Justice Sonia Sotomayor’s acceptance of that right as a reason why he opposed her nomination.

During the next president’s first term, four Justices will not only near or pass the recent average retirement age for the position, but all four will exceed or be on the verge of exceeding the average life expectancy for their genders. If Rubio wins and any three of these four aging Justices who support Roe — Anthony Kennedy, Ruth Bader Ginsburg and Stephen Breyer — leaves the court, that would be end of a constitutional right to control your own pregnancy.

If President Rubio were able to replace all of the court’s octogenarians, that would be the beginning of a conservative majority that could last until the middle of this century.

Photo: Gage Skidmore via Flickr.