Originally Posted by Patrick Crusius, from his own manifesto the day of the shooting
https://randallpacker.com/wp-content/uploads/2019/08/The-Inconvenient-Truth.pdf

The inconvenient truth is that our leaders, both Democrat AND
Republican, have been failing us for decades. They are either complacent or involved in
one of the biggest betrayals of the American public in our history. The takeover of the
United States government by unchecked corporations. I could write a ten page essay on
all the damage these corporations have caused, but here is what is important. Due to
the death of the baby boomers, the increasingly anti-immigrant rhetoric of the right and
the ever increasing Hispanic population, America will soon become a one party-state.
The Democrat party will own America and they know it. They have already begun the
transition by pandering heavily to the Hispanic voting bloc in the 1st Democratic Debate.
They intend to use open borders, free healthcare for illegals, citizenship and more to
enact a political coup by importing and then legalizing millions of new voters. With
policies like these, the Hispanic support for Democrats will likely become nearly
unanimous in the future. The heavy Hispanic population in Texas will make us a
Democrat stronghold. Losing Texas and a few other states with heavy Hispanic
population to the Democrats is all it would take for them to win nearly every presidential
election. Although the Republican Party is also terrible. Many factions within the
Republican Party are pro-corporation. Procorporation pro-immigration. But some
factions within the Republican Party don’t prioritize corporations over our future. So the
Democrats are nearly unanimous with their support of immigration while the
Republicans are divided over it. At least with Republicans, the process of mass
immigration and citizenship can be greatly reduced.

That is clearly not "right wing" or "pro-Trump" or motivated by Trump. And is clearly motivated by POLITICAL considerations, as he headlines that clause of his manifesto.
NOT racial reasons.
He clearly does not identify himself as a Republican or a Trump supporter, or as a racist. He is clearly critical of the Republican party.

And...

Quote
America is full of hypocrites who will blast my actions as the sole result of
racism and hatred of other countries, despite the extensive evidence of all the problems these
invaders cause and will cause. People who are hypocrites because they support imperialistic
wars that have caused the loss of tens of thousands of American lives and untold numbers of
civilian lives. The argument that mass murder is okay when it is state sanctioned is absurd. Our
government has killed a whole lot more people for a whole lot less.
Even if other non-immigrant targets would have a greater impact, I can’t bring myself to kill my
fellow Americans. Even the Americans that seem hell-bent on destroying our country. Even if
they are shameless race misers, massive polluters, haters of our collective values, etc. One day
they will see error of their ways. Either when American patriots fail to reform our country and it
collapses or when we save it. But they will see the error of their ways. I promise y’all that.
I am against race mixing because it destroys genetic diversity and creates identity problems.
Also because it’s completely unnecessary and selfish. 2nd and 3rd generation Hispanics form
interracial unions at much higher rates than average. Yet another reason to send them back.
Cultural and racial diversity is largely temporary. Cultural diversity diminishes as stronger
and/or more appealing cultures overtake weaker and/or undesirable ones. Racial diversity will
disappear as either race missing or genocide will take place. But the idea of deporting or
murdering all non-white Americans is horrific. Many have been here at least as long as the
whites, and have done as much to build our country. The best solution to this for would be to
divide America into a confederacy of territories with at least 1 territory for each race. This
physical separation would nearly eliminate race mixing and improve social unity by granting
each race self-determination with their respective territory(s).

For a "white racist", he repeatedly makes reasoned and impassioned economic and political arguments for why he is NOT a racist.

Granted he's a crazy man for planning to shoot dozens of innocent people and then actually doing it. But his logic as best I can grasp it is that he intended it to preserve the U.S.'s sovereignty, environment, and national cultural identitty.