Will Republicans ever win another election ever again?

Trump may win this election, but Trump is most likely the last Republican president due to naturalizing people primarily from nonwhite countries when nonwhites vote left-wing.  One can look to the civics and demographics of California to see what the future of the US entails, unless incompetent and confused Republican leadership immediately change course (they won't, Republicans believe in legal immigration).

Yes, like this year.

There are any number of elections they'll win, yes.

Hopefully not but there are a lot of stupid people. 

why yes, of course.
As long as these people vote: 
" those people are still overwhelmingly less violent than Antifa, "
yes. they only kill people by running them over with their cars.

Given all the 3 YEARS of outright PATHETIC, FAILED BLUNDERING by the Democrats in their effort to politically discredit President Trump--I'd say THEY pretty much guarantee PRESIDENT TRUMP'S 2020 RE-ELECTION!!

Trump's a classy guy: He'll find some savvy way to thank Nancy, Chuck, AOC and Omar, for another FOUR YEARS as POTUS.

Probably, people have short memories when it comes to politicians.

Yep, and lots of them in November. 

There are many factors that play into this.
Increased immigration favors the Democrats.
The current draconian policies that Democrat governors from NY, MI, WA and VA have implemented will cost them votes in the long run.
Especially if the voters believe that the current policies are based more on political considerations than public safety.
Then we have the fact that the Democratic party is being pushed further left by Democrat politicians like AOC.
There is growing discontent in the Democratic party where the ultra left of the party does not want to play nice with anyone.
That will likely cause a split in the Democratic party.
If this happens then the Republicans could have a greater chance of getting elected.

The RepubliCON traitors are dead as is their ancient platform. 

A Republican Presidential candidate will probably never win the popular vote again in my lifetime. They have only won it once since 1988!