Richard Grenell, nominee to be US ambassador to Germany, testifies during a Senate Foreign Relations Committee hearing on Capitol Hill in Washington, DC, September 27, 2017. (SAUL LOEB/AFP/Getty Images)
CNN  — 

President Donald Trump is increasingly agitated at the slow pace of confirmations in the Senate and blasted Democrats Monday for delaying votes on many of his nominees to top government posts – including his pick to be ambassador to Germany.

“Hard to believe Obstructionists May vote against Mike Pompeo for Secretary of State,” Trump tweeted. “The Dems will not approve hundreds of good people, including the Ambassador to Germany. They are maxing out the time on approval process for all, never happened before. Need more Republicans!”

Trump was highlighting the long-stalled nomination of Richard Grenell, a close political ally and his choice to be the top US diplomat in the major European country. Many Democrats loudly oppose Grenell and are refusing to give consent for a quick vote on his confirmation, even though there are likely enough GOP votes to confirm him.

Grenell, who if confirmed would become one Trump’s highest profile gay appointees, is a Republican who worked with Trump’s national security adviser John Bolton at the United Nations. He was one of the President’s earliest and most vocal foreign policy supporters, vociferously backing the real estate magnate at a time when many in the Republican foreign policy establishment were publicly and staunchly opposed to his candidacy.

Axios reported Monday that Grenell was spotted at Mar-a-Lago talking to Trump over the weekend. Sources close to Grenell said that Trump has told him he wants him to play a broader role in Europe beyond Germany, and that was true since his nomination – even before Bolton was in the picture.

But his road to confirmation has consistently faced opposition. Last month, Sen. Jeff Merkley, an Oregon Democrat, formally held up the vote on Grenell, saying on the Senate floor he couldn’t support a nominee who “tweets attacking both prominent Democratic women and prominent Republican women.”

On Monday, Merkley’s spokeswoman Martina McLennan told CNN that the senator is disturbed by Grenell’s “significant history of making misogynistic and other incendiary statements online.”

“Mr. Grenell has also been dismissive of the threat of Russia’s meddling in the US, a fact that is doubly concerning as Germany is one of our closest and most important allies in pushing back on Russian aggression on the world stage,” she said in the statement.

A Democratic leadership aide told CNN on Monday that besides Merkley, there are multiple Democrats with concerns about Grenell. That means McConnell must move to break the filibuster, just as he has done scores of times before to get Trump’s nominees confirmed.

German Chancellor Angela Merkel is set to visit Washington on Friday – and if Republicans want to confirm Grenell by the time she arrives, McConnell would have to act quickly.

Grenell’s nomination has already passed through the Senate Foreign Relations committee but with Democrats objecting to a vote, McConnell has not yet taken the time consuming procedural steps to overcome their filibuster.

The problem for McConnell is that it can eat up multiple days of precious floor time to break a filibuster if opponents choose to drag out the process. McConnell has made it his priority to break filibusters on top Cabinet and sub-Cabinet posts as well as appeals and district court judges, whose work can last decades not just until the end of the president’s term.

Don Stewart, a spokesman for McConnell, acknowledged Republicans will have to file cloture to get Grenell confirmed but wouldn’t say when they plan to do it.

“Grenell is a priority. Because of the well-documented Democratic obstruction, there are a lot of priority nominees to get through,” Stewart said.

But Grenell has found vocal support from a prominent gay rights groups. The Log Cabin Republicans, as well as Stuart Milk, the co-founder of the Harvey Milk Foundation and Harvey Milk’s nephew, support his nomination and have been pushing for him to get confirmed.

“The votes are there to confirm (Grenell), we know that,” Gregory T. Angelo, the president of the Log Cabin Republicans, told CNN. “We have been working in support (of) his confirmation even before he was nominated … we need a formal and official chief presence in Germany.”

And Milk, who said the Trump administration has “overall has been life negating for our community and for other minorities” supports the nomination as well.

“Having someone like (Richard) Grenell – who has been a staunch supporter of marriage equality and global LGBT rights, someone who was even was forced off the Mitt Romney campaign by social conservatives because he was openly gay - having Ric at the diplomatic table, even if that table is more homophobic, makes it that much harder for our community to be on their menu,” Milk said in a statement to CNN.

In April, McConnell also blamed Democrats for blocking Trump’s nominees.

“Unfortunately, for more than a year now, our Democratic friends used the partisan playbook to delay and obstruct even the least-controversial nominees,” he said on the Senate floor. “So unless we can reach the kind of bipartisan agreement that was once the norm, and process noncontroversial nominees more promptly, we’re left with no choice but to proceed the hard way.”

Meanwhile, the Senate is also dealing with the confirmation of Pompeo – who will likely be filibustered by opponents – and a circuit court nominee who is being filibustered.

CNN’s Elise Labott contributed to this report.