Impeachment is a political process, not a legal one. As long as the GOP hold a majority in the Senate, the president cannot and will not be impeached. The evidence would have to be overwhelming and it would have to have political consequences to the Republican party's base and the president's base. Short answer: No, it does not make him vulnerable to impeachment.
From Wiki:
At the federal level, Article I, Section 2, Clause 5 of the Constitution grants to the House of Representatives "the sole power of impeachment", and Article I, Section 3, Clause 6 grants to the Senate "the sole Power to try all Impeachments"
In short, even if the process can be started, the majority Republican senate will not impeach the president of their party because partisanship is a guiding factor in today's politics.. it is more important to protect the party, rather than be fair or objective.
Side note: There is even a question of whether a sitting president can even be indicted for a crime. A memo to the Attorney General in 2000, implies that this can't happen...
There are . . . incidental powers, belonging to the executive department,
which are necessarily implied from the nature of the functions,
which are confided to it. Among these, must necessarily be
included the power to perform them, without any obstruction or
impediment whatsoever. The president cannot, therefore, be liable
to arrest, imprisonment, or detention, while he is in the discharge
of the duties of his office ....
Bolding was me.
The point here, is impeachment is difficult when the ruling party controls half the process and has absolutely no intention of following through, even if the president committed a crime, which he also might have immunity to as well due to the responsibilities of the President.
UPDATE:
Partisanship
The current political culture is extremely partisan. Just to set the tone here. American political culture is at a point where reality has come into question. When it comes to Democrats and Republics, they literally cannot agree on basic facts. This comes is from a long history of deeply partisan politics. Whether it's the economy or a simple state of the union. The best evidence of this was the breaking of norms on President Obama's Supreme Court nominee. Mitch McConnel literally refused to bring to the senate.
To continue, the Republican party was extraordinarily partisan in blocking the nomination.
McConnel-
"I can now confidently say the view shared by virtually everybody in my conference, is that the nomination should be made by the president the people elect in the election that's underway right now,"
Further bolstering McConnell's decision was a Tuesday announcement by all 11 Republicans on the Senate Judiciary Committee, led by Chairman Charles Grassley, R-Iowa, that the panel would not move forward with any consideration of Obama's nominee.
The very unique precedence:
Despite the stolen Supreme Court seats of the mid-1800s, says Geyh, the modern Senate’s outright declaration that no Obama nominee would get a hearing or vote in 2016 still violated the Senate’s norms. None of the tabled nominees of the 1800s were federal judges like Garland, whose qualifications the Senate endorsed in 1997 by confirming him for his appeals court seat, 76-23. “You’ve got a consensus choice,” says Geyh, “which makes it all the more bald-faced that the Senate would do as it did.”
Extreme partisanship and violation of norms. It's clear that any push for impeachment would be made with more violation of norms and more partisanship. All the evidence supports the position.
Update:
Polarization:
I'm putting in a section about polarization to give context to my response because it's important.
Polarization is gridlock and assuming that an environment is more polarized, then it is more gridlocked.
As I explore in Stalemate, the frequency of legislative deadlock increases as the parties polarize. Over the postwar period, congressional performance runs closely in tandem with the size and strength of the political center. As the figure below suggests, as legislative “moderation” declines, Congress and the president more frequently deadlock over the salient issues of the day.
The folks at the Brookings Institute concluded:
Increasing political polarization in recent decades has made it much more difficult for the U.S. government to work effectively. According to a multiyear cooperative study by the Brookings and Hoover Institutions, political elites are now more sharply divided than are citizens, and the latter are more likely to place themselves at the ends rather than in the middle of the ideological spectrum than they were as recently as the 1980s. Having a smaller political center to work with, even leaders committed to bipartisan compromise have found such agreement harder to come by.
Ii bi-partisan compromise is harder to come by, then it would naturally follow that an impeachment from one party, regardless of which party it is; would likely meet with obstruction at the next step by the opposing party. So in the current context, a Democratic House and a Republican Senate. It is likely that anything the house does will be blocked by the senate and this is a product of polarization, not specific parties.
