A defining week in politics will clarify the choice Americans will face in November in a fateful and unprecedented election that is already testing long-held interpretations of the Constitution and the powers of the presidency. The Supreme Court could deliver a ruling in a momentous case as early as Monday, on the Colorado Supreme Court’s decision to throw ex-President Donald Trump off the ballot because of the 14th Amendment’s ban on insurrectionists.Trump is meanwhile expected to emerge from the 15-state Super Tuesday GOP primaries within touching distance of a third straight Republican nomination. As he seeks a stunning White House return four years after trying to overturn the last election, the ex-president is showing a new term would be even more extreme than his first. President Joe Biden, meanwhile, will take the stage before a huge television audience two nights later for his State of the Union address. It’s a critical test for an 81-year-old commander in chief facing deep doubts that he’s fit to serve a second term as he’s beset by global crises and disappointment with his performance at home. A race between the current president and the ex-president is one that polls show many Americans dread. But Trump and Biden’s turns in the spotlight this week will highlight their all-but-certain rematch, barring health crises or other surprise events. Biden is highly vulnerable in a race that has no clear leader, according to the CNN Poll of Polls average. November’s election is already heaping pressure on political and electoral institutions, the Constitution and America’s fragile national unity. The country has never had an election in which one candidate faces multiple criminal trials and is running on the false premise that he was illegally ousted from power. The Supreme Court does not disclose in advance which opinions it will issue. But all eyes are on the justices in case they decide the Colorado case before voters there take part in their Super Tuesday primary. Trump’s name will appear on ballots that were printed weeks ago. But without a ruling from the justices, there was no guarantee voters who pick Trump would have their choice counted if justices decided he was ineligible to serve.