If Senate Majority Leader Harry Reid (D-Nev.) loses his bid for re-election this fall, he won’t be the only one feeling despair. K Streeters’ angst already is palpable about Reid’s potential leadership-slot successors — presumably either Sen. Dick Durbin (Ill.), the current Majority Whip, or Sen. Charles Schumer (N.Y.).

[IMGCAP(1)]”There is great fear in the business and tech community about Durbin taking over as Majority Leader,” one K Street veteran explained.

If Durbin’s ascension inspires dread in some downtown corridors, a Majority Leader Schumer isn’t a favorite of those in the influence business, either. But Schumer, the Senate’s No. 3 Democrat and a former head of the Democratic Senatorial Campaign Committee, has the bigger footprint downtown.

And lobbyists, of course, prefer familiarity.

“I’m not sure if he’s liked,” a longtime Democratic lobbyist said of Schumer. “But he is the better known of the two, and there is more comfort about his operating style and how you work with him. There’s just not the comfort there with Durbin.”

Another prominent Democratic lobbyist said Schumer has more ties to people downtown, but “frankly neither Schumer or Durbin, they’re not either of them like a downtown person.”

Neither Schumer’s nor Durbin’s offices would comment for this column. A Durbin spokesman said, “We’re not going to comment on these kinds of stories, these ridiculous stories.”

Lobbyists don’t have an official role in Congressional leadership fights — should there even be a leadership fight — but they can wield considerable influence when it comes to helping Members add to their war chests.

Both Senators come from states with huge money centers, which provide plenty of campaign currency. And they are both on committees, Schumer in particular, that attract private-sector interests. Schumer sits on the Banking, Housing and Urban Affairs and Finance panels, while Durbin has a seat on Appropriations.

“For people like Schumer and Durbin, K Street is such a small part of the money they raise,” one well-connected Democratic lobbyist said.

In the 2010 election cycle, Schumer is the favorite with lobbyists. He has raised a whopping $207,970 from lobbyists to Durbin’s $9,500, according to election data compiled by the nonpartisan Center for Responsive Politics.

But before you count Durbin as a K Street pariah, consider this: Schumer is up for re-election this year, while Durbin just won a third term in 2008. And when you compare Durbin and Schumer’s lobbyist donations over the past six years, Durbin actually pulls way ahead. Lobbyists, according to the center’s data, make up Durbin’s fifth-biggest industry donor with $344,412. In the 2008 cycle, when Durbin was up for re-election, he collected $216,212 from lobbyists.

Advocates in certain sectors prominent in Illinois — think agriculture and commodities — favor Durbin.

But when it comes to personality, Schumer seems the better fit.

Schumer has cultivated a style with lobbyists that downtown denizens describe as forceful and aggressive. “He’s very proactive from a legislative standpoint,” one senior Democratic lobbyist who has lobbied Schumer explained. “If you have a pretty good issue and a pretty good case, he can be accessible, and he’s [educable]. And he can be effective if he chooses to be proactive. On the other hand, you just as soon not be on the losing side of an effort by him, either. Those skills — high energy, drive — can work the other way.”

Lobbyists describe Durbin as a more reserved personality compared with Schumer’s booming profile.

“Traditionally, [Durbin] hasn’t been quite as accessible to as wide an array and wide a variety of interests as Sen. Schumer,” the senior Democratic lobbyist said.

Even one lobbyist who likes Durbin said the Illinois Senator “keeps his own counsel” and does not operate smoothly on K Street.

“One of my frustrations is we could do so much more for the party out of Chicago, but [Durbin] has not really made that a priority,” this lobbyist said. “He does not do much with lobbyists.”

This lobbyist added that K Streeters are often frustrated with Durbin’s office. “He doesn’t really do meetings with lobbyists that often. And because there’s floor duties now, he doesn’t do as many meetings as he used to. In meetings, he’s very engaging.”

As for who they think would win a Schumer vs. Durbin duel, most Democratic lobbyists interviewed put their money on Schumer.

“I think downtown there’s an assumption that this is Chuck Schumer’s race to lose,” said a lobbyist who leans toward Durbin. “I’m not convinced of that, especially since it would be a secret ballot. Certainly everybody in the caucus is indebted to Schumer, but politically they probably line up more with Durbin.”

One Democratic lobbyist who engages in fundraising for the party said that even though the safe money goes to Schumer, a third option could materialize. “Particularly depending on what happens with the election, you might hear people talking about needing big change, and then maybe you see one of the newer Members emerge” — like Sen. Claire McCaskill (D-Mo.), this lobbyist noted. “Alliances form in different ways.”

Another prominent K Street Democrat agreed. “You never know about a dark horse, especially if the two of them engage in some sort of self-cancellation.”

Either way, lobbyists’ power over the situation is limited.

“Members and the staff feel it is very much an inside game and that people on the outside should not have a role in it,” the fundraising Democratic lobbyist said. “Our job mostly is to observe and speculate.”