Even as Sen. Evan Bayh (Ind.) reasserts himself as one of the Democratic Conference’s squeakier wheels, neither his leadership nor Senate Republicans are giving his recent actions more than a passing glance.

In opposing the $410 billion omnibus spending bill, including in an opinion piece in the Wall Street Journal, Bayh was bucking President Barack Obama and jeopardizing a priority of Senate Majority Leader Harry Reid (D-Nev.). But Democrats and Republicans, noting Bayh is up for re-election next year in conservative-leaning Indiana, said the Democratic Senator’s actions are nothing new and are far from a signal that he intends to lead a rebellion of Democratic moderates.

“Evan has very strong feelings about things that are important to him, and he represents his state’s interests and the country’s interests the way he feels best, and I have great respect for that,— Sen. Byron Dorgan (D-N.D.) said.

Reid and other Democratic leaders have struggled to overcome Republican-led filibusters on spending bills this year, including the recently passed $787 billion economic stimulus. So with a host of White House initiatives on the way that affect the federal books, from the fiscal 2010 budget to environmental and health care legislation, Bayh’s support and influence on his fellow Democratic moderates could prove crucial.

Bayh, along with Sens. Tom Carper (D-Del.) and Blanche Lincoln (D-Ark.), has been helping assemble a gang of Democratic moderates to put a centrist stamp on fiscal issues.

In doing so, the Indiana Democrat has shown that he isn’t afraid to say no to Reid when it counts, as he did last year when his opposition to a budget bill forced the Majority Leader to negotiate with the Republicans. Last Congress, the Senate was near an even split, as opposed to the current 58-41 Democratic majority.

But at least for now, Democrats aren’t agitated over Bayh’s defections.

“He’s a nonentity,— a senior Democratic Senate aide said. “He doesn’t spend a lot of time worrying about leadership, and leadership doesn’t spend a lot of time worrying about him.—

And one former Senate Democratic leadership aide said Bayh’s occasionally independent positions on issues, while against the majority will, have not created any lasting friction with top Senate Democrats. Although Bayh’s moves might sometimes irritate, his leadership understands Indiana politics and realizes that the Hoosier State Democrat is on the ballot in 2010, the former aide said.

Bayh, a former governor who briefly sought the presidency in 2008, responds simply that his actions on the omnibus bill and other fiscal matters reflect his beliefs. He said that there are no hard feelings between him and the Senate Democratic leadership, and that his recent positions have zero to do with the fact that he is running for re-election next year.

“To get balanced budgets, sometimes you have to cut spending in tough times,— Bayh said Wednesday in an interview. “I think our leadership is pretty good about understanding that people need to vote their conscience.—

Bayh has a long record as a moderate, centrist politician on fiscal and foreign policy matters. Obama’s narrow victory in Indiana in 2008 was the first by a Democratic presidential candidate in at least a generation, but even in the 1980s and 1990s when Republicans dominated, Bayh was successful.

Indiana Republicans concede Bayh has maintained a sterling personal reputation and strong political standing at home by periodically burnishing his conservative credentials — he voted with the Democrats on the stimulus but opposed the omnibus. Bayh is given high marks for his political skill, and GOP strategists familiar with his career say it hasn’t hurt that his father, Birch Bayh, is a popular former Senator.

At home, Bayh is considered a “moderate to conservative Democrat,— with voters on the far right and far left “despising— him, and the rest — about 80 percent — approving, said one GOP operative based in the Hoosier State. A typical Hoosier’s characterization of the Senator, this operative added, is something along the lines of: “He’s not like those Washington Democrats.—

For Republicans, Bayh proves an occasionally timely cross-aisle ally on fiscal matters.

The Senator’s opposition to the omnibus, and his choice of the Wall Street Journal to air his objection nationally, was widely circulated by the GOP and used by them to make their point that the spending bill was too large and overloaded with pork . The legislation ultimately passed Tuesday night thanks to the support of several Republicans, though not any from among the GOP leadership.

“We did think that his observations about the omnibus were right on point, and we appreciated his opposition,— Senate Minority Leader Mitch McConnell (R-Ky.) said.

But in contrast to moderate Democrats such as Sen. Ben Nelson (Neb.) and Sen. Joe Lieberman (ID-Conn.), whose positions on foreign policy are almost uniformly in line with the GOP, Bayh is not seen by the Republicans as a reliable compatriot.

Bayh generally keeps a low profile in the Senate, and Republicans do not expect him to become a high-profile Democratic dissenter, even given the far-reaching budget implications of the president’s various programmatic proposals. As is typical of Bayh, he downplayed the attention that he received as a result of opposing the omnibus, chalking it up to the fact that Obama only recently assumed office.

“He’s like a Brigadoon,— one senior Republican Senate aide said of Bayh. “He appears every so often on the Republican side, only to suddenly vanish, leaving conservatives to endlessly search in vain for his vote.—

Emily Pierce contributed to this story.