Which investment banking firms lean towards the right, and towards the left, politically?

There's a fair amount of political diversity within investment banking. A few archetypes that are pretty common (with the approximate proportion of people in my experience who fall into each bucket):

The Limousine Liberal (15%): Sees higher taxes as conducive to creating a thriving society. Cares about environmentalism, DE&I to an extent, but reads the New York Times for politics and the New York Post for lifestyle and wants the streets to be kept clean and cares about law & order and maintaining a comfortable life. The kind of guy who wants to pay for great public schools in society, but will ultimately have his kids sent to private school. Also tends to be well traveled and cultured. No problems voting for Biden or Elizabeth Warren, but thinks Bernie Sanders and Cornel West are perfect examples of progressive losers who are financially irresponsible and can't even manage their own houses.

Young Democrat (15%): Generally a junior banker. Registered Democrat. Votes for Biden. Has opinionated views on abortion, drug legalization, and sometimes student debt cancellation. May morph over time into a Wall Street Journal Conservative or a Limousine Liberal.

The Wall Street Journal Conservative (25%): Doesn't get much news from social media or television, but reads the WSJ and WSJ Opinion section religiously. Rejects Fox News as having gone off the deep end. High admiration for Reaganites and Goldwater-era Republicans. Wants lower taxes for the trickle-down effect on the economy. Sees America as a shining city on the hill which should be a world leader through economy, innovation, military power, and diplomacy. Views Eisenhower favorably. Views Biden's infrastructural projects with some level of respect, but sees other aspects as irresponsible helicopter money. Thinks DE&I is a hollow farce and has contempt for it, but generally thinks of themselves as being inclusive and fair to all people. 

Mainstream MAGA Hat Republican (25%): Rejects Reaganite Republicanism and has fully embraced Donald Trump. Sees Donald Trump as a strong and charismatic leader who is defending the country from the corrupting influences of DE&I, wokeness, and infiltration of the country through immigration. More occupied with social matters and culture than economic policy like taxes or trade. Watches Fox News.

Deep MAGA Hat Republican (15%): Similar to above, but angrier with Joe Biden and other politicians for their perceived corruption. Regularly follows latest scandals of the "Biden Crime Family." Watches OAN, Newsmax, or reads specialized accounts on Telegram. Sometimes pays some lip-service to Q theories by calling various political leaders "pedophiles" or part of a "cabal." Sees the WEF, the IMF, and a whole slew of Alphabet Soup organizations as part of a grand globalist conspiracy to subvert America.

Anarcho-Capitalist (5%): More strongly deregulationary than the Wall Street Journal Conservative and wants an even stronger reduction of the size of the government. Thinks the government should be involved in the military and little else. Calls for repeals of Medicare, Medicaid, and the ACA, with substantial cuts to government bureaucracy. Follows Argentina's president Javier Milei closely as validation of their economic worldview. Reads the WSJ Opinion section, National Review and white papers from the Cato Institute and the Heritage Foundation.

I've met a few social democrats or democratic socialists in the industry, but these are few and far between.