The only excuse that can be given by Republicans for voting for Roy Moore is that they don’t want to lose the Senate.

This logic ignores the fact that the U.S. Senate map is very favorable to the GOP, no matter what President Donald Trump’s approval rating is.

Making Moore a U.S. Senator, however, will cost the Republican Party in 2018, 2020 and beyond.

When women came forward to describe how Roy Moore touched them as teenagers, one being as young as 14, some voters believed them. Others claimed that the accusations were media or Democrat fabrications. Yet a significant number of conservatives, from Alabama no less, sought to defend Moore’s actions using a variety of excuses.

It was enough to make this father of a 14-year-old cringe, as people talk about excusing, even mainstreaming, the sexual assault of teens. It’s definitely not Christian.

Others who believe the accusers, including the Alabama Governor, have cited the need for party control of the Senate to trump all other considerations.

It’s led Donald Trump to endorse Moore (after Trump backed sitting Alabama GOP Senator Luther Strange in the primary) and the Republican National Committee (RNC) to re-endorse him. It’s a poor political strategy that will punish the GOP for years to come, and here’s why.

Analysts know that 2018 is a good year for Republicans.

GOP hand-wringing comes from setbacks the party suffered in the two 2017 gubernatorial races, both of which were won by Democrats (taking Chris Christie’s seat and losing in a Southern state). But here’s where they are wrong.

First of all, Hillary Clinton won both states in 2016, so this was not unexpected.

Second of all, the GOP won all of the special election Congressional seats (Georgia, Montana, Kansas, South Carolina, etc.) that opened up in 2017, so the year was not unkind to Republicans.

In fact, the Democrats have to defend nearly three times as many seats as Republicans do in 2018.

Only two Senate seats (Arizona and Nevada) are considered having any chance for a Democrat to win.

Meanwhile, Democrats have many incumbents to defend in many red states won by the Republican Party in 2016 (North Dakota, Montana, Indiana, Missouri, West Virginia). Even Democrats in purple states taken by Trump (Ohio, Florida, Pennsylvania) have a fight on their hands. Do the math. Losing only two Senate seats would be a good outcome for the Democrats. If Doug Jones wins, the GOP will hold or even expand their Senate numbers.

But now look at the map if accused pedophile Roy Moore is sitting in the Senate.  There are enough Christians in this country who believe the accusers, and can see those who know better endorse Moore just to get an extra vote on taxes. Having Trump say “Merry Christmas” a lot in December won’t make up for this cynical excuse of a terrible sin.

Ever wonder why Republicans always ran against Ted Kennedy in every state since the early 1970s?

Other senators were more liberal, and Kennedy was good at reaching across party lines. It’s because people across the country knew that Kennedy got away with a terrible crime. As of the 1974 election, Democrats led in the House by a 291-144 margin, and had a 60-38-2 advantage in the Senate. Six years later, the GOP won the Senate and took the House in 1994, dominating legislative politics ever since, still running against Kennedy and his ghost.

Had they expelled him, the Democrats would be in much better shape than the mess they are in now.

It will be that way for the GOP with Roy Moore, unless voters with a conscience pick retired Marine Colonel Lee Busby, or voters stay home, or the GOP listens to their own senators who say no to Moore. They know what’s at stake here, even if the Steve Bannons of the world love Roy Moore.

John A. Tures is a professor of political science at LaGrange College in LaGrange, Georgia.  He can be reached at jtures@lagrange.edu. His Twitter account is JohnTures2.