WASHINGTON (MarketWatch) — It might seem premature to start picking a running mate for Joe Biden in 2016, since he hasn’t even decided whether he will enter the race for the Democratic presidential nomination.

But forecasting what a Democratic ticket could look like is an exercise that can help assess not only his chances of winning, but whether he should even run at all.

And there are a couple of tickets that look pretty decisive.

As the impact of the vice president’s “Late Show” interview last week with Stephen Colbert seeps through — a rare and unvarnished view of a politician as a human being — the support for Biden among Democrats will continue to surge. Watch interview, Part 1 and Part 2

There are moments that capture the political imagination of the public — Barack Obama’s speech at the 2004 Democratic Convention, Ben Carson’s speech at the 2013 National Prayer Breakfast — and Biden’s interview with Colbert is likely to be one of them.

The name that comes up most often as a potential running mate for Biden is Massachusetts Sen. Elizabeth Warren, especially after the two held a “secret” meeting last month.

But pairing Warren, who is 66, with the 72-year-old Biden would invite ridicule of the Democrats for offering a Medicare ticket. And some Democrats fear a Massachusetts taint in a nationwide race.

Warren would indeed energize the party’s progressive wing, but Vermont Independent Sen. Bernie Sanders is already doing a great job of that. Sanders would fade quickly if Biden offered another alternative to Clinton and those energized voters would fall in line behind the vice president.

Sen. Kirsten Gillibrand of New York would be the first choice as a running mate for Joe Biden. ANDEL NGAN/AFP/Getty Images

So the first choice for a running mate for presidential nominee Biden would be New York Sen. Kirsten Gillibrand, 48, a rising star in the party who would no doubt be in the primary race herself if Hillary Clinton had not pre-empted the party establishment for her run.

Gillibrand won 72% of New York’s vast and diverse electorate in her 2012 re-election, after a 2010 special election confirmed her 2009 appointment to the Senate seat vacated by Hillary Clinton when she became secretary of state.

Gillibrand launched her political career in 2006 by besting a four-term Republican incumbent in the 20th Congressional District in upstate New York, which was widely viewed as leaning conservative and a safe Republican seat.

Gillibrand was moderately conservative during her House tenure, joining the Blue Dog faction. However, she has become notably more progressive in the Senate, carving out legislative leadership niches on issues like sexual assault in the military and campus safety.

In the 2016 race, she would bring a fresh face to the national Democratic Party, a proven fundraising ability, and the state with the third-largest number of electoral votes.

And, to state the obvious, her presence on the ticket could soothe those disappointed in Clinton but eager to see a woman in national office. By the same token, she would almost certainly be precluded from being Clinton’s running mate.

Second choice would be former Massachusetts Gov. Deval Patrick. He was an effective and popular two-term governor in a populous state and gave a stirring speech at the 2012 Democratic convention.

However, he does have that Massachusetts taint and as an African-American he might seem too much like Barack Obama redux.

Hillary Clinton’s downward spiral seems more difficult to reverse with every new poll that shows her losing support.

A new ABC News/Washington Post poll out this week shows Clinton down 21 points from her July number, dropping from 63% to 42%. While this is still ahead of Sanders’ 24% and an undeclared Biden’s 21%, the trend is clear. Tellingly, Clinton’s support among women has plummeted from 71% to 42%.

A CNN/ORC poll late last week showed a similar drop, as Clinton’s support fell to 37%, down 10 points from August and 19 points from July, while Sanders registered 27% in the latest poll and Biden, 20%.

Biden has had a long career in national politics, joining the Senate in 1973 at age 30 as the youngest member then and the sixth-youngest in history. In January 2017, he would be the oldest person ever inaugurated as president.

But it was not only a veteran politician the public saw on the Late Show last week, but a person of maturity and depth next to whom most other candidates seem shallow or shifty.

It would not be hard to see him, if he chooses to run, as winning the Democratic nomination and, with the right ticket, winning the election a year from November.