You're wrong twice within the first twenty words. Google doesn't donate to all candidates, and there are U.S. corporations of its size that don't make political contributions at all.
'idlewords has actually done a great job of getting tech workers to pressure their employers into ceasing the political donations. It's inspiring to see someone manage to make a dent like he has. A quick brush on his twitter will verify what he's saying, here.
> Could you name one or two of those that are Google's (Alphabet's) size don't contribute?
All of them, including Google, because they are legally prohibited from it.
Google's PAC donates, but not with Google funds, because corporate PAC donations can't come from corporate treasury funds.
There are some large companies that lobby but don't operate PACs (IBM and Apple for instance.) It's debatable whether this is better or not, but it's certainly a different shape of political engagement.