By Tuesday or Wednesday Kansans will likely have a new U.S. senator. For most of the last century, we could simply assume that the state would elect the Republican nominee, especially if the candidate was the incumbent representative from the Big First district, per Bob Dole, Pat Roberts and Jerry Moran.

But 2020 has proved different, with the first truly competitive Democratic candidate emerging since Rep. Bill Roy gave Sen. Dole all he could handle in 1974.

The race between two physicians, Republican Rep. Roger Marshall and Democratic state Sen. Barbara Bollier, remains too close to call, although a Bollier win would be regarded as a significant upset. Still, all the major national handicappers have the race at “Leans [or Tilts] R,” which means that such a result might well occur.

What we do know is that either Bollier or Marshall will win the seat and serve for the next six years, and probably beyond, given Kansas’ tendency to reelect its U.S. senators.

So, what will happen if we elect either Bollier or Marshall?

Given present trends, polling and forecasts, Democrats are likely to capture the Senate and the presidency, although neither is a sure thing. And Democrats will almost certainly continue to control the House. Nate Silver, the noted election forecaster, sees a 71% chance of a Democratic trifecta of the presidency, the Senate and the House.

If that is so, Sen. Marshall would become a low-ranking member of a Republican minority, whose chances to regain a majority don’t look good until 2024 at the earliest. Given strong parties in Washington, he would have relatively little influence, although individual minority-party senators have far more power than their House counterparts.

Of course, if Trump were to win and bring in a Republican Senate with him, all that would change.

For Sen. Bollier, the Democratic trifecta offers a far more positive outlook. Most important, she would be part of a governing majority that would be poised to pass significant legislation on coronavirus relief, the economy and health care, among other major issues.

In addition, if Bollier wins the election, she will not be the 50th or 51st Democrat in the party’s majority. Winning Kansas would mean that Democrats would likely win other close races as part of a Blue Wave.

If Bollier is, say, the 53rd Democratic senator, she would have substantial leverage in various ways. First, she would have great flexibility to negotiate with Democratic leaders; if she banded together with other moderates, they could substantially affect Democratic policies. Indeed, Sen. Nancy Landon Kassebaum long played such a role.

Second, as an upset winner from a red state, Bollier would be treated well by Majority Leader Chuck Schumer and other party leaders. They would like nothing more than to hold onto a Kansas seat well into the future.

Following from this, a third advantage for Bollier would be to win appointment to key committees that would serve both her interests and those of the state. Thus, seats on Agriculture and HELP (Health-Education-Labor-Pensions) would be obvious choices, but she might well gain a seat on a more powerful panel, such as Appropriations or Finance.

In the end, Kansans are voting for an individual Senate seat, but all seats are not created equal. For Kansans, a seat for Barbara Bollier would likely be far more valuable than one for Roger Marshall.

• Burdett Loomis is an emeritus professor of political science at the University of Kansas.