At least 16 Democratic members of Congress donated to Cuellar’s campaign through their campaign committee or leadership PACs during the 2022 election cycle, according to an OpenSecrets analysis of FEC filings. In total, the campaign received some $40,400 in political contributions from other sitting Democrats.

Not sure on 2020 numbers, they’re not as quick to find. Not exactly breaking the bank here though. Almost half of his funding that cycle (almost 2 million) actually came from AIPAC, and a lot of the rest from industry and business contributions.

https://www.opensecrets.org/news/2022/08/democratic-leadership-corporate-interests-help-rep-henry-cuellar-fend-off-primary-challenge/

Anyways, details are important. When we look at them, we see a lot more than some sort of “party suppression”.