US President Donald Trump is expected to announce his Supreme Court nominee on Tuesday evening local time in Washington D.C. Weeks into his presidency, Trump's decision marks an early chance for him make a lasting impact beyond his term or terms in office. Presidents before him have often used the nomination to stack the court with someone who adheres to their ideology.

The Supreme Court of the United States is the head of the country's judiciary, and any judges nominated serve for life. Only eight justices currently serve on the bench.

Trump right now is expected to select a justice who is ideologically in line with the deceased Justice Antonin Scalia, a political conservative and Constitutional "originalist," meaning he took the founding document of the United States literally. The text was not to be interpreted.

The frontrunners

Three names have been floated to replace Scalia, following the failure of the previous Congress to hold a hearing for US President Barack Obama's nominee, Merrick Garland, while he was still in office.

Judge Neil Gorsuch from the Colorado Court of Appeals is considered somewhat of an intellectual successor to Scalia, and also boasts the strong Ivy League pedigree typical of many Supreme Court Justices.

Another rumored Trump choice is William Pryor of the Alabama court system. He is known to be an opponent on abortion rights.

The last name floating around Washington has been Thomas Hardimann of Pennsylvania, who is known for defending of the rights of gun owners.

Can the Democrats put up a fight?

But beyond the question of who Trump will pick lies the question of what the Democrats can do to oppose the confirmation of a Justice misaligned with their party's values.

"The stakes have been heighted by the unwillingness of the Republican Congress to hold hearings on President Obama's appointment for ten months last year," said Professor Paul Schiff Berman, the Walter S. Cox Professor of Law at the George Washington University, "and by the fact that Trump was not elected with a majority of the popular vote. The Democrats represent more voters than the Republicans."

"They will need to show they are willing to fight for the American values that the people in the streets protesting are trying to argue for," Berman added.

Depending on how much resistence the Democrats put up to the nomination, the next question begs what kind of precedent this fight will set for the rest of the legislative agenda during Trump's presidency.

"Are the Democrats going to try to pay back the Republicans (for blocking Obama's nominee)?" asked Jon Gould, Professor of Law and Public Affairs at American University.

Gould predicted this may not even be a huge showdown that could come if one of the more liberal Supreme Court Justices were to either retire or die in office. "It's possible this is simply replacing a Scalia vote with another Scalia vote," he said.

That is, that whoever is nominated would be so ideologically similar to the deceased Scalia that the makeup of the bench would not change.