Barack Obama will forever be known as the first black president. He’ll be remembered as the first president to speak to the Muslim world from a Muslim country. Many will reflect on his dependence on the teleprompter, and that he was the first President to have a blackberry, and third sitting President to win the Nobel Peace Prize. President Obama will have a lot of defining moments. And though he might be on his way out in two -- or even 6 -- years, long after he’s left the Oval Office, Elena Kagan, if confirmed, just might be Obama’s biggest, and most potent  legacy, making her vetting all the more critical.

The highest court in the land is responsible for some of the most dramatic policy outcomes in our country’s history. Now, more than ever before, we find key issues of importance front and center of the judicial branch and Elena Kagan could be the tipping point in their outcomes, like the fate of the sweeping, highly unpopular health care bill.

Eighteen states have already filed legal challenges through their attorney generals against Obama’s key initiative to date, the health care legislation, and five more states joined as recently as last week. The joint lawsuit led by Florida was filed on March 23 by mostly Republican attorney generals. It claims the sweeping reform of the $2.5 trillion U.S. health care system, jammed through by Democrats in the Congress after months of manipulation; nasty partisan fighting violates state-government rights in the U.S. Constitution and will force massive new spending on hard-pressed state governments.

In addition to the pending lawsuits, bills and resolutions have been introduced in at least 36 state legislatures seeking to limit or oppose various aspects of the reform plan through laws or state constitutional amendments making the fate of this giant legal challenge – the constitutionality of the health care bill – likely to end up at the door of the Supreme Court, thus on Kagan’s desk.

And what about immigration reform? With states like Arizona taking steps of their own to solve their undocumented alien crisis, and more states poised to follow suit, the question of whether or not Kagan will rule in favor of the Tenth Amendment is a confirmation hearing imperative. Already opposition groups have made clear they'll challenge the Arizona law, including Obama's Attorney General himself, Eric Holder. Under the Tenth Amendment, “the powers not delegated to the United States by the Constitution, nor prohibited by it to the States, are reserved to the States respectively, or to the people.”

It could be years before we see comprehensive reform on immigration, but depending on the final product, the issue is likely to make its way to the highest court in the nation. Kagan, again, could determine the fate of the ruling and set precedent.

Besides issues on health care, immigration, and states’ rights, expect Kagan to have influence over game changing eminent domain cases where the government has been involved in power grabs with people’s land. The court is also likely to face cases on regulation of the Internet, military issues like Don't Ask, Don't Tell, campaign finance, potential environmental decisions, the Fairness Doctrine, religious freedom and perhaps most importantly -- the federal government and the War on Terror. All of these are areas where President Obama or his administration will have weighed in, making them part of his legacy.

Thanks to a complacent, love struck media, our current president wasn't tested and vetted as he should have been. Like Obama, Kagan doesn't have a robust paper trail so we are unable to discern her judicial temperament and philosophy because she’s never been a judge. That's why it’s terribly important that she gets a good grilling, under very rigorous questioning in the Senate.

Elections have consequences, and Supreme court nominees embody these consequences. At only 50 years old, a Justice Kagan, is likely to stay on the highest court for the next 30-40 years and will rule on the most serious and sensitive decisions in our country's history – making her appointment pivotal -- and her future ultimately Obama’s potential past.

Andrea Tantaros is a FoxNews.com contributor and conservative columnist. Follow her on Twitter @andreatantaros. 

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