President Trump is fighting a two-front war against the Russia investigation that threatens to engulf his presidency and the Republican congressional leaders he doesn't think are doing enough to further his legislative agenda.

To succeed on either front, Trump will need friends on Capitol Hill. Some Republicans are privately saying the president must pick one of these battles.

The need for congressional support has always been obvious when it comes to passing Trump-friendly bills. You can't legislate without the legislative branch. Monday brought fresh reminders that alliances on the Hill are necessary for coping with Russia too.

Consider the reports that high-level Trump business associates sought Russian President Vladimir Putin's help on a stalled Moscow construction project while their boss was running for president. One even said in an email that building a Trump Tower in Moscow would help him win the presidential election, a jarring claim given Russian interference in the 2016 campaign.

What kind of benefit of the doubt Republicans choose to give Trump on such stories will go a long way to deciding how he weathers the storm. One Republican operative, requesting anonymity so as not to publicly criticize GOP congressional leaders, argued the party's lawmakers are already too quick to run to the microphones to criticize Trump.

"Would a Democratic Congress have so many investigations open into President Clinton or Obama?" the operative asked. "Would [Obama Attorney General] Loretta Lynch have recused herself?"

Surveying both the latest revelations and Trump's recent Twitter barbs at Senate Majority Leader Mitch McConnell, R-Ky., and House Speaker Paul Ryan, R-Wis., a second Republican operative requesting anonymity to speak candidly about the president offered a stark assessment.

"Trump is well on his way to alienating the remaining Republicans in Congress who support him with the continued allegations from Russia and if these continue, his agenda is definitely finished," the second GOP operative said, going on to note that Democrats would be tempted to pursue impeachment if they win back the House in 2018 and Republicans are tired of the "drip, drip, drip."

But impeachment cannot succeed without significant bipartisan support, one of the reasons House Minority Leader Nancy Pelosi, D-Calif., has always been cool to the idea. Pelosi helped keep the antiwar Left from going very far in pushing impeachment when she was speaker during George W. Bush's presidency.

Articles of impeachment can be advanced by a bare majority of the House, which means Trump's exposure increases if Democrats reclaim the speaker's gavel for Pelosi. Removal from office, however, requires a two-thirds Senate majority Democrats are never likely to have. Partisan impeachment bids don't work.

Republicans needed 12 Democratic votes to convict former President Bill Clinton in the Senate in the late 1990s. They couldn't even get one. Democrats need 19 to do the same to Trump under the current partisan breakdown of the Senate. They'd still need 15 if those numbers flipped to a 52-48 Democratic majority, no sure bet even in a good election cycle for the Democrats given the GOP-friendly Senate map.

If special counsel Robert Mueller's investigation doesn't uncover clear-cut collusion between the campaign and Russian election meddlers or obvious proof of crimes like obstruction of justice, his report could make the case that Trump is hopelessly conflicted on Russia because of past business dealings — something that will require judgment calls from Congress, especially the Republicans.

"Whatever Trump thinks of Mitch McConnell," the first GOP operative said, "he'll need him."

Instead there seems to be growing distrust between Trump and Republicans on Capitol Hill. The president, a newcomer to government with a long history of running his own businesses, is noticeably frustrated with the slow pace of change in Washington.

Many Trump supporters believe he is going to have to call out Congress, even members of his own party, if he is ever going to get anything done. White House press secretary Sarah Sanders has explicitly said in a briefing that the "endgame" of Trump's tweets and other complaints was to get Congress to "do its job and actually pass legislation."

"President Trump was elected to shake up Washington and get big things done for the American people. Period," said Erin Montgomery, communications director for the pro-Trump America First Action. "That won't be comfortable for the status quo, but President Trump is fighting for the millions of Americans who are tired of the excuses and are demanding results. So, whether you're Democrat or Republican, either embrace the moment and join the movement, or get the hell out of the way."

There are still plenty of Republican lawmakers siding with Trump on the Russia probe, among other things. Rep. Ron DeSantis, R-Fla., filed an amendment that would block Mueller from investigating "matters occurring before June 2015," which is when Trump announced his presidential campaign.