This post by /u/The_Alaskan has an answer that partly answers your question, at least on the topic of Republican papers and commentators (rather than representatives themselves)
The quick summary is: many partisan papers and at least some influential party members supported him in the early stages of the allegations due to his track record and the (relatively) weaker evidence, but support withered as evidence piled up
Well, were they plagued?
Let's take a look at the folks in the House Judiciary Committee who voted against the articles of impeachment in July 1974. There were 21 Democrats and 17 Republicans on that committee. All the Democrats voted in favor of at least two of the three articles. Only two Democrats voted against the third article:
Walter Flowers, D-Alabama, was re-elected in 1974 with 91 percent of the vote (no Republican ran against him) and served until he decided to run for U.S. Senate in 1978. He lost the primary that year and retired from politics. Flowers at the time was seen as one of the key votes on the articles of impeachment, and even he thought he might vote against impeachment. In the end, he decided that "if we didn't impeach, we'd just ingrain and stamp in our highest office a standard of conduct that's just unacceptable."
James Mann, D-South Carolina, was re-elected in 1974 with 63.3 percent of the vote and served until he decided against running for re-election in 1978. Mann helped revise the articles of impeachment to gain wider support in the eventual full vote of the House (which never happened because Nixon resigned). His 2010 obituary in the New York Times called him "one of the South's most eloquent voices on the [impeachment]." “We would strive to strengthen and preserve the presidency,” Mann said in 1974. “But if there be no accountability, another president will feel free to do as he chooses. The next time there may be no watchman in the night.”
One Republican, Lawrence Hogan of Maryland, voted in favor of all three articles of impeachment. He didn't seek re-election but instead tried to become governor of Maryland. He lost in the Republican primary, and his son said in a subsequent interview that he believes it was because Hogan abandoned his party, and voters didn't like that. Hogan himself said in 1988 that he assumed he would lose the governor's nomination as a result of his vote, but he tried to convince the Maryland public anyway. Hogan ran 15-minute ads on Maryland TV to explain why he was voting for impeachment. He wrote a letter to his GOP colleagues to urge them to vote for impeachment:
“While the travesties of Watergate were perpetrated outside the regular channels of Republican Party organizations, they were all committed by Republicans for the benefit of a Republican president. Do we want to be the party loyalists who in ringing rhetoric condemn the wrongdoings and scandals of the Democratic Party and excuse them when they are done by Republicans?”
Hogan died just three months ago, and much of the information above is taken from his Washington Post obituary.
Five Republicans voted "yes" on two articles of impeachment:
M. Caldwell Butler, R-Virginia was re-elected in 1974 and served until he decided against running for re-election in 1982. "Watergate is our shame," he said in 1974, and went on to become so popular in his southwest Virginia district that he ran unopposed in his last two elections.
William Cohen, R-Maine was re-elected with 71.4 percent of the vote in 1974 and served until he decided to run for U.S. Senate in 1978. He won that election and served in the U.S. Senate until the 1996 election. President William Jefferson Clinton appointed him Secretary of Defense, and he served in that capacity until George W. Bush became president.
Hamilton Fish IV, R-New York was re-elected with 65.3 percent of the vote in 1974 and was re-elected until 1994, when he dropped out of another re-election bid because of a prostate cancer diagnosis. He died in 1996.
Edward Froehlich, R-Wisconsin lost his re-election bid to Democratic candidate Robert John Cornell, who beat him by almost 10 percent of the vote.
Robert McClory, R-Illinois, was re-elected in 1974 and served until he decided against running in 1982.
One Republican voted "yes" on one article of impeachment. Tom Railsback, R-Illinois was re-elected in 1974 with more than 65 percent of the vote. He was re-elected thrice more, but after the 1980 census, Illinois was redistricted, and he lost his primary to a more conservative Republican (who went on to lose the general election).
Continued below ...